Heat 2 tablespoons of olive oil in a large skillet (big enough for the mushrooms to fit in a single layer without crowding) over medium-high heat.
Add the mushrooms to the skillet and toss them to coat evenly with the oil.
Spread the mushrooms in a single layer. Cook without stirring for 4 to 5 minutes, until the mushrooms brown on the edges and reduce in size by about half. If the pan starts to look dry during this process, add a bit more oil.
Stir the mushrooms and cook for another 2 minutes without stirring to ensure they are fully cooked.
Add the garlic to the skillet, and cook until fragrant, being careful not to burn it, about 30 seconds.
After the garlic is fragrant, add the chopped parsley or other fresh herbs, then reduce the heat to medium-low.
Add the butter and cook for 3 to 4 more minutes, stirring frequently, until the butter has melted and coats the mushrooms.
Remove from heat and serve the mushrooms immediately.
Notes
Cleaning Mushrooms Properly: Gently clean your mushrooms using damp paper towels to wipe away dirt. This method avoids waterlogging the mushrooms, which can happen if washed with water. Waterlogged mushrooms tend to absorb water and won’t brown nicely when sautéed.
Avoid Overcrowding the Pan: Cook your mushrooms in a large enough pan to spread out in a single layer without touching each other. If the pan is overcrowded, the mushrooms will steam and release water, preventing them from achieving that desirable sautéed texture.
Do not be afraid to turn up the heat!When sautéeing mushrooms, they need to sear (not steam) for the best flavor. Light olive oil has a high smoke point so it won’t burn like butter. This allows cooking at a higher temperature so the mushrooms can brown. I use medium-high heat, but it depends on the stove.
Let the Mushrooms Caramelize: For best results, resist the urge to stir the mushrooms constantly. Allow them to sit and cook undisturbed. This method helps them reduce in size and develop golden, caramelized edges. Once they’ve reduced by about half, stir them, add the butter, and then let them cook for another two minutes without stirring for even caramelization.
Don’t skimp on the oil – Because mushrooms are so absorbent, they’ll absorb oil quickly and may burn if there’s not enough oil in the pan. Keep an eye on them when cooking. If the pan dries out, add more oil.