Gently clean the mushrooms using a paper towel or a mushroom brush to remove any dirt. Slice them into thick pieces, approximately ½ inch in thickness.
In a carbon steel skillet, heat the olive oil and butter over medium-high heat until the butter has melted and the mixture is hot.
Just before cooking, quickly toss the mushrooms with the soy sauce. Avoid doing this step in advance, as it will draw out too much moisture from the mushrooms.
Add the mushrooms to the heated pan, tossing them to coat in the butter and oil mixture. Let them cook undisturbed for 4-5 minutes, allowing one side to develop a rich, golden-brown sear.
If desired, pour in the white wine and let it cook down, enhancing the flavor of the mushrooms. Add the minced garlic and thyme to the pan, stirring occasionally. Continue cooking for another 3-4 minutes, or until the mushrooms are tender and infused with flavor.
Finish by seasoning with salt and pepper to taste. Garnish with chopped fresh chives if desired, and serve warm.