Pound chicken breasts between two pieces of waxed paper to about 1/2 inch thick. In a bowl, mix lemon juice, olive oil, garlic, salt and pepper. Put chicken in a single layer in a large ziplock and fully cover with marinade. Let sit on the counter for about 20 minutes (no longer than 30ish).
While chicken marinates, slice onion, and tomato, get spinach, cheese and pesto ready, get bread either grilled or toasted. Turn on grill and grill chicken for about 4 minutes per side. Smear 1 tablespoon goat cheese on the bread, top with chicken and pile on the remaining goods and enjoy!
Serve with a fresh green salad on the side.
Go to full version of