For The Best Grilled Mushrooms, Steam Them

But before they can concentrate and brown, mushrooms need to give up some of the abundant water and air that makes them spongy when raw. The method I’m going to suggest might sound counterintuitive, but stay with me: The best way to rid mushrooms of air and water is to cook them in water.

This was a game-changing discovery that Senior Editor Lan Lam made while working out her sautéed mushroom technique, and it actually makes great sense. If you start cooking mushrooms with a dry-heat method such as sautéing or roasting, their surfaces dry out and become insulative barriers that prevent their interiors from cooking through. But surrounding mushrooms with moist heat quickly collapses their air spaces and helps them shed their own liquid. Once drained, they can be briefly seared to concentrate their flavor and brown.

Here’s my method, which will work for any variety with a cap that measures at least 2 inches in diameter. (The mushrooms will shrink during cooking so anything smaller runs the risk of slipping through the grill grate.) The steaming step can even be done ahead of time, so you can have keep ready-to-sear mushrooms handy for anytime the mood strikes. 

1. Microwave 1 pound mushrooms with some water in bowl. After a few minutes, they’ll shrink by about a third and amount of liquid in bowl will double, indicating that they’ve given up a good bit of their air and moisture. 
2. Rest mushrooms, covered, for about 5 minutes to finish cooking. 
3. Drain mushrooms well. Let them stand at room temperature while you prepare grill, or store them in fridge for up to 24 hours. 
4. Toss mushrooms with a little vegetable oil, salt, and pepper. 
5. Grill mushrooms on hotter side of a hot two-level fire (cover grill if using gas), flipping every two minutes until well browned on all sides.

They'll taste great as they are—woodsy and smoky with concentrated sweet-savoriness—but you can also upgrade their complexity by tossing them with herbs, sauces, oils, or basting them with a seasoned butter.