Begin by patting the chicken thighs dry with paper towels to ensure a good sear. Season both sides generously with salt and pepper while you slice the cremini mushrooms into thick pieces.

In a cast-iron skillet or heavy-bottomed pan, melt 2 tablespoons of butter over medium-high heat. Once the butter is bubbling vigorously, add the chicken thighs skin-side down. Sear for 6–8 minutes until they develop a golden-brown crust. Flip the chicken and cook for another 3–4 minutes until browned, then set aside.

Using the same skillet, lower the heat slightly. Add another tablespoon of butter if necessary. Add the chopped onion and minced garlic, sautéing until the onion is translucent, about 3–4 minutes. Next, add the sliced cremini mushrooms and cook until browned and tender, about 5 minutes.

Pour in 1 cup of chicken broth and 2 tablespoons of soy sauce, scraping up the browned bits from the bottom. Return the chicken thighs to the skillet, ensuring they are nestled in the liquid. Cover and let them simmer for 10–12 minutes, or until the internal temperature reaches 165°F.

Carefully plate the chicken thighs and spoon a generous amount of the mushroom sauce over the top. Garnish with fresh herbs if desired.