Start by preparing your chicken breasts. If they’re particularly thick, you might want to pound them to an even thickness. This ensures they cook evenly.
In a bowl, combine the soy sauce, lemon juice, Worcestershire sauce, minced garlic, and smoked paprika. Place the chicken breasts in this marinade and let them sit for at least 30 minutes. The longer, the better.
While your chicken is marinating, heat the olive oil in a skillet over medium heat. Add the sliced onions and sauté until they’re just beginning to soften, about 3-4 minutes. Next, throw in the sliced mushrooms. Cook until both vegetables are tender and slightly caramelized. Set them aside.
In the same skillet, add a bit of butter and let it melt over medium-high heat. Place the marinated chicken breasts onto the skillet. Cook for about 5-7 minutes on each side or until fully cooked. Season with salt and pepper.
Once your chicken is about done, place a slice of Monterey Jack cheese on each breast. Cover the skillet with a lid for about 1-2 minutes, allowing the cheese to melt splendidly over the chicken.
Finally, top each cheesy chicken breast with the sautéed onions and mushrooms. Let everything meld together for another minute or two.
