1-First, get your chicken ready by slicing the 2 large boneless, skinless chicken breasts into 2-3 thinner pieces and pounding them to about ¼ inch thickness. Pat them dry and season with salt, pepper, garlic powder, and 1 tablespoon Italian seasoning, then dredge in a mix of ½ cup flour and ¼ cup shredded Parmesan cheese. This step ensures even cooking and adds a nice crust.

2-Next, heat 3 tablespoons olive oil and 1 tablespoon butter over medium-high heat in a skillet, then sear the chicken for about 3 minutes per side until it’s golden brown. Set it aside and cover with foil to keep it warm. For the sauce, melt 2 tablespoons unsalted butter and 1 tablespoon olive oil in the same skillet, scraping up those tasty browned bits.

3-Add the sliced 3 yellow onions and cook for 5 minutes until they start to soften, then mix in 1 tablespoon low sodium soy sauce, 1 teaspoon dried rosemary, 1 teaspoon dried thyme, and ¼ teaspoon ground sage. Cover, lower the heat, and cook for 30 minutes, stirring now and then. After that, uncover and cook over medium heat for another 10 minutes to fully caramelize the onions.

4-Once the onions are ready, add 3 cloves minced garlic and ½ cup dry white wine, cooking uncovered until the wine mostly evaporates, about 10 minutes. Sprinkle in 2 tablespoons flour and cook for 1-2 minutes to get rid of the raw taste, then stir in 1 cup beef broth, 1 cup chicken broth, and 1 beef bouillon cube. Bring it to a gentle boil and let it thicken for 3-5 minutes before removing from heat.

5-Preheat your oven to 475°F (245°C), then put the chicken back in the skillet or an oven-safe dish along with any juices. Top with 2 cups of cheese like mozzarella, provolone, Swiss, or Gruyere, and bake for 15-20 minutes until the cheese bubbles and browns. For dietary tweaks, try using tofu instead of chicken for vegan options, as mentioned in other sections.