Mushrooms are the meatiest vegetable — both in texture and flavour — which is why it shouldn’t be surprising that they take quite well to a marinade. And, unlike meat, the sponge-like ‘shrooms absorb flavour fast, which is always good news for the impatient.
If you're chasing a perfect sear, mushrooms are a huge pain to deal with. Whether or not you rinse them, slicing and chopping alone releases enough of their natural moisture that even previously bone-dry mushrooms can turn soggy before they hit the pan - and that simply won't do.
But what of browning? Exposing mushrooms to more liquid than is absolutely necessary to clean them is supposedly a big no-no, but I’ve found that marinated mushrooms brown and crisp just fine as long as you pat them dry with a paper towel. In fact, depending on what’s in your marinade, they may brown even faster. (Sugar has a tendency to do that.)
You can use your favourite meaty marinade on the mushrooms, but I’ve found oil-based concoctions and brines work best.
If you want to go the oil-based route, you can enlist your favourite vinaigrette (or ginger dressing), or combine two parts oil, one part vinegar, and one part sugar (or honey, or syrup), along with herbs, spices, peppers, or any other flavour boosters you have lying around.
Vinegary brines such as pickle juice also work well, as does any sort of fermenting liquid you have hanging out in your fridge. (Kimchi mushrooms, anyone?)
If you’re working with larger ‘shrooms, tear them into manageable pieces, scraping out the gills first if you’re dealing with portobello. Cover the pieces with your marinade, let them hang out for half an hour to an hour, pat them dry with paper towels, then sauté or roast as usual.