Start by preheating your oven to 375°F (190°C). This allows your oven to be ready for the chicken after searing.

Season the chicken breasts with salt and pepper. On a plate, mix flour with more salt and pepper, then dredge the chicken in this mixture—don't forget to shake off the excess.

In an oven-safe skillet, heat 2 tablespoons of olive oil over medium-high heat. Sear the chicken for a few minutes on each side until it turns golden, then transfer the skillet to the oven to bake for a short time.

Add butter and the rest of the olive oil to the same skillet. Sauté the mushrooms for about five minutes until tender.

Stir in the minced garlic, onion powder, mustard powder, and thyme, cooking for an additional minute to release their fragrant aromas.

Pour in the bouillon mixture along with the apple cider vinegar. Scrape up any browned bits from the bottom as you mix everything together to intensify the flavor.

Return the chicken to the skillet, tilting it to coat in the sauce. Let it cook for a few more minutes until the sauce thickens beautifully.