Gorgonzola Chicken with Basil Pesto

Create the pesto: Combine basil leaves, 2 1/2 tablespoons olive oil, walnuts, Parmesan cheese, and garlic in a food processor; process until smooth.

Prepare the chicken: Heat 1 tablespoon olive oil in a large skillet over medium-high heat. Cook chicken until it reaches a golden brown color, about 5 minutes per side. Transfer the cooked chicken to a serving platter.

Cook and stir mushrooms in a single layer in the same skillet until they are tender, about 5 minutes. Add onion and cook until it becomes translucent, about 5 minutes. Add garlic and cook for a short period of time, until fragrant, approximately 30 seconds. Add half of the Gorgonzola cheese and cook until it starts to melt slightly. Pour in wine and stir to loosen any browned residue from the bottom of the skillet. Stir lemon juice, chicken broth, brown sugar, salt, and black pepper into the sauce.

Bring the chicken broth mixture to a boil; reduce heat and simmer until the sauce is reduced by a quarter, 3 to 5 minutes. Stir in pesto and return the chicken to the skillet. Cook until an instant-read thermometer inserted into the center reads at least 165 degrees F (74 degrees C), about 5 minutes more. Add the remaining Gorgonzola cheese and chopped tomatoes.

Serve each chicken breast on a plate, topped with the sauce.