First Step: Prepare Ingredients. Begin by trimming and halving the chicken breasts lengthwise. Pound them gently to about 1/4 inch thickness for even cooking. Clean and blanch asparagus by snapping off the woody ends and boiling spears in salted water for 2-3 minutes until crisp-tender. Drain, rinse with cold water, and set aside. Slice mushrooms thickly, finely dice onions, and mince garlic.

Second Step: Cook Mushrooms and Aromatics. Heat 1 tablespoon butter and 2-3 tablespoons olive oil in a large skillet over medium-high heat. Sauté the sliced mushrooms until golden and soft, about 5 minutes. Add diced onion and continue cooking until translucent. Stir in garlic, half of the sea salt, black pepper, and 1 tablespoon parsley. Remove mixture from the pan and set aside to preserve texture.

Third Step: Sauté Chicken. In the same skillet, add remaining olive oil and butter. Season chicken breasts with the rest of the salt and pepper. Cook chicken breasts for about 3-6 minutes per side, depending on thickness, until golden brown and cooked through. Remove chicken to a plate.

Fourth Step: Make Madeira Wine Sauce. Deglaze the skillet with Madeira wine, scraping up browned bits from the bottom. Boil and reduce wine by half, then add beef broth. Simmer until liquid reduces to about a quarter of the original volume (10-20 minutes). Optionally stir in cornstarch slurry and add cream to enrich the sauce. Season with Worcestershire sauce and thyme if desired. Adjust salt and pepper to taste.

Final Step: Combine, Bake, and Serve. Return chicken breasts to the skillet or transfer everything into an oven-safe dish. Layer sautéed mushrooms and reserved asparagus on top. Sprinkle shredded mozzarella cheese evenly. Broil or bake at 400°F (200°C) for 5-7 minutes until cheese is melted, bubbly, and golden. Garnish with fresh parsley and serve immediately with sides like mashed potatoes or angel hair pasta.