Wipe any dirt from the mushrooms with a damp paper towel; DO NOT rinse them.
Slice the mushrooms if they aren’t pre-sliced.
Heat a large 12-inch skillet over medium-high heat. Add the mushrooms in a single layer without overcrowding the pan.
Allow the mushrooms to brown and release water. Let the water evaporate completely until the pan is dry.
Stir gently as needed, then allow the mushrooms to brown again until they reach your desired color.
Reduce the heat to low or remove the pan from the heat. Add butter, fresh thyme, and other aromatics.
If using unsalted butter, sprinkle a little salt.