In a medium bowl, combine 2 ½ cups of beef broth, 1 chicken bouillon cube, 1 teaspoon soy sauce, 1 teaspoon onion powder, ½ teaspoon mustard powder, and ½ teaspoon dried thyme. Stir until the bouillon cube dissolves.

In a sealable container, combine 3 tablespoons of cornstarch with 3 tablespoons of cold water. Shake until well mixed.

Gently rinse 10 ounces of mushrooms and pat dry. Slice large mushrooms if necessary.

Slice the chicken breasts lengthwise into 2-3 thinner portions; pound if they are too thick.

In a skillet, melt 2 tablespoons of salted butter over medium-high heat. Sauté the mushrooms for 3-4 minutes on each side until golden brown.

Season chicken with salt and pepper, then dredge in all-purpose flour.

In the same skillet, heat olive oil over medium-high heat and cook chicken for 4-5 minutes on each side until golden brown.

Remove excess oil from the skillet, pour in ½ cup dry white wine and add minced garlic. Cook until the wine reduces by half.

Add the broth mixture to the skillet and bring to a gentle boil. Reduce sauce for 10 minutes, stirring occasionally.

Add cornstarch mixture while stirring, and cook until the sauce thickens.

Stir in ⅓ cup heavy cream and add sautéed mushrooms back into the skillet.

Return cooked chicken to the skillet, spoon sauce over, and heat for about 5 minutes.

Serve warm over mashed potatoes or buttered noodles.