Mushrooms are one of the most common badly-prepared foods. Most people (and restaurants) just do not cook them well. You're more likely to get a poorly-cooked mushroom at most restaurants than you are to get a correctly cooked one.
I cannot tell you how many times I've been served bloated, watery, flavorless mushrooms as a side or over a steak or in a pasta. Or (even worse) those canned button mushrooms. And how about when places put thick slices of raw mushrooms on a pizza and you end up with a watery mess all over the top of your pizza because the mushrooms sogged out the whole thing? Blech!
Mushrooms are not something that are difficult to cook! What is the problem here?
Well, I think it goes back to two things; patience and ignorance.
In order to cook mushrooms well, one must know that mushrooms are 90-94% water. And water is the enemy of flavor. So dispensing with the ignorance is step one. Once you know that mushrooms are mostly water (and water has no flavor), anyone can arrive at the logical conclusion that cooking mushrooms correctly involves getting rid of all that water.
The second part--patience--is related to the first. Getting all the water out and cooking mushrooms well involves a little time. Really, not all that much, though. Again, this is a technique that's not difficult, but so few people manage to do it right. So, although I've said often enough that this blog isn't about recipes, I'm going to post a step-by-step walk-through of how I cook mushrooms.
First, the product. What kind of mushrooms? I use crimini, which are sometimes called 'brown' mushrooms. They look just like button mushrooms, but the caps are brown instead of white. I don't buy button mushrooms because I feel they lack flavor. Incidentally, crimini mushrooms are the same as portabellos, it's just that portabellos have been allowed to grow more mature and larger. That's why you'll sometimes see mushrooms labeled "baby portabellos". This is just marketing, though, so don't be fooled into paying more for them. They're still just your basic crimini or 'brown'.
I do sometimes get fancier types of mushrooms like chanterelles (when I can find them), shiitake, oyster, or morels (around April or May, when my father-in-law in Iowa starts bringing me five pound bags of them he buys at his local pub!), but for this post, I'm going to stick to talking about the basic everyday crimini.
Ok...pre-cooking. I wash my mushrooms by submerging them in a large container of water, swishing them around, and then pulling them out of the water, leaving the dirt and grit behind. This runs counter to everything you always read about how you're supposed to just wipe the dirt off with a paper towel or use some sort of vegetable brush or something so that the mushrooms don't soak up all the water when you wash them. I figure, if they're already 90+% water, how much more can they soak up? And it doesn't matter, because I'm just going to cook all the water out of them anyway.
Next, slice them. Don't worry too much about trying to cut them evenly or so the slices look nice. They're going to shrink down so much when they cook that it hides sloppy knifework.
While you're slicing them, put a saute pan on the heat. You want the pan to start getting hot, but you don't want it screaming hot when the mushrooms go in. Start the dry pan on a lower flame, and then put a decent amount of olive oil on the bottom of the pan right before you add your mushrooms. Add them all at the same time. You'll feel like you're overloading the pan, but pile'em in there. Crank the heat to high or medium high, grind some pepper over them, throw some kosher salt on the top, drizzle a little more olive oil on the pile, and then wait a little while.
You'll hear a bit of sizzling at first, but as soon as the mushrooms start to get hot and actually cook, the water will start coming out of them, and then you won't hear any sizzling. Instead, you'll hear the sound of water boiling, which is what you want. The water is coming out of the mushrooms and cooking away.
This takes a while, so you can go tend to other things in the kitchen, or get your aromatics together. I use whole herbs and whole garlic cloves to flavor my mushrooms. I almost always use whole sprigs of thyme and rosemary, and garlic. These flavors work really well with mushrooms and, unless I'm cooking a dish that those flavors would really clash with, that's what I use.
At this point, lots of water is coming out of the mushrooms and the big pile is starting to shrink a bit. If you click on the picture to the right, you can see that there's a lot of water around the sides of the pan and in the center. That water needs to completely cook away before the mushrooms actually begin to saute, and therefore, start browning (and developing flavor). Getting rid of the mushroom water also serves to concentrate the flavor, since that water does actually have some mushroom flavor in it. By reducing that water down until it disappears, you're leaving all the flavor components behind in the pan, where they'll adhere to the mushrooms. This is why pouring off the water (as some recommend) is ill-advised. Pouring off all that water amounts to pouring off a lot of flavor as well. We want mushrooms that have a really good, strong mushroomy flavor.
You'll be able to hear when all the water has cooked away. The sound will change from a boiling water sound to a frying mushroom sound. This is what you want. Moderate your heat a bit here and add your garlic cloves and herb springs. Just lay them on the top and don't move the pan around too much. Allow the mushrooms that are in contact with the pan to develop a nice brown crust. You may need to add a bit more oil here, depending on how much the mushrooms have soaked up. If it starts to smell like the mushrooms are burning, add more oil or lower your heat. Or both. But don't obsess too much about the color. You'll see why in a bit. Once they've had a few minutes to start browning, you can move them around a bit. Use a heatproof rubber spatula to loosen them from the bottom of the pan, then flip them in the pan or stir them with the spatula. Try and keep moving them around so they all have a chance to get some time on the bottom of the pan. The browning really develops the flavor we're going for.
Once you get a nice amount of browing, it's time to deglaze the pan. I use white wine most of the time, but sometimes I use red, if that makes more sense in the context of the dish in which they're going to be used. For instance, if I'm going to use the mushrooms in a beef stew that utilizes red wine in the cooking, I'll use red to deglaze. Most of the time, though, I stick with white because it allows me to use the mushrooms more flexibly. If you wanted to really get fancy, you could use Marsala or Madeira, both of which will add a really nice nutty caramelized note to the finished product.
The wine serves a few purposes; it stops the sauteing process, it picks up all the little brown bits (fond) that are stuck to the pan and puts them back onto the mushrooms, and it adds some sweetness and some acidity to the flavor of the finished product. I like to deglaze twice with mushrooms. I'll deglaze once, allow the liquid to cook all the way down until the pan is dry and the mushrooms begin to saute again, and then I deglaze a second time and, again, bring the liquid all the way down until it's dry. What this does is it ensures that all the fond comes off the bottom of the pan and onto the mushrooms, and it allows the sugars from the wine to caramelize, contributing to the browning.
Once you deglaze, you'll be able to see the color difference almost immediately. Rather than having some mushrooms that are pretty brown and some that are still very pale, it will begin to look more homogenous, taking on a more even brown color after deglazing, and this will happen again after the second deglazing.
This why you don't really need to worry too much about the color while you're sauteing, since most of the color comes during the deglazing, where it gets pulled off the bottom of the pan and spread around throughout the mixture.
Note; I use my French carbon steel pans for cooking mushrooms. You could use a good stainless/aluminum pan, or cast iron is always good, but do not use a non-stick pan, since the pan won't develop the brown fond on the bottom and this will change the finished product.
Once you've deglazed twice, cook the liquid down until the pan is dry and the mushrooms begin to saute again. Move them onto a tray or shallow pan to stop the cooking process, and then taste and adjust the seasonings, if necessary. You can discard the garlic and herb sprigs at this point--their flavor has been infused into the mushrooms--and it's also good to add a couple pats of butter to the mushrooms while they're still warm.
Another note; if you're doing multiple types of mushrooms (crimini and, say, oyster), you need to go through this process separately for each type of mushroom, and then mix them together at the end. Different mushrooms cook at different rates.
I like to buy big packs of criminis from Costco and do this in really big batches. That way, I've got cooked mushrooms ready to add to any dish that I might be cooking. They go great in pastas, on top of pizzas, over soft polenta, in a quiche or scrambled eggs, fried into a hash with diced potatoes, as part of a stir-fry, or just on their own, served over a steak or as a side dish.