Clean mushrooms by gently wiping with a paper towel or using a mushroom brush.
Slice into thick 1/2-inch slices.
Add butter and oil to a large skillet and heat over medium high heat.
In a large bowl, quickly toss the mushrooms and soy sauce; do not do this ahead of time as this will remove too much moisture from the mushrooms.
Add the mushrooms to the pan and toss with olive oil mixture.
Do not stir, as you allow to cook about 4 - 5 minutes without disturbing, to brown on one side.
Add white wine and allow to evaporate.
Add garlic and thyme.
Continue cooking an additional 3 - 4 minutes, stirring occasionally, until cooked.
Remove from stove and season with salt and pepper to taste.
