In a bowl, mix together balsamic vinegar, Dijon mustard, liquid aminos, a pinch of salt and pepper, and your choice of dried herbs.
Place the chicken breasts in a Ziploc bag and pour the marinade over them. Make sure they’re well-coated. Seal and refrigerate for at least 30 minutes.
Prepare the Chicken
Preheat your oven to 375°F (190°C).
Take each chicken breast and make a pocket in the middle using a sharp knife. Stuff this pocket with mozzarella.
Place the stuffed chicken in a baking dish. Add in the sliced onions and halved garlic around the chicken.
Bake
Pour the remaining marinade over the chicken.
Place the baking dish in the oven and bake for 25-30 minutes or until the chicken is cooked through.
Bruschetta Topping
While the chicken is baking, prepare the bruschetta topping. In a bowl, mix together the quartered cherry tomatoes, diced red onion, chopped basil, and season with salt and pepper.
Final Touch
Once the chicken is done, take it out of the oven and immediately top it with your freshly made bruschetta mixture.