In a 9x13 baking dish or 10-inch cast iron skillet with high sides, add the butter and place in the oven to melt. About 5 minutes.
Remove from the oven and add the onion, garlic, chicken stock, rice, and salt. Wrap tightly in foil and bake until the rice is soft and creamy--about 35 minutes.
Remove from the oven and stir in the chicken, cheese, tomatoes and basil. Switch your oven to broil and broil on high until the cheese is just starting to brown and the tomatoes shrivel a bit--5 to 6 minutes. Just keep an eye on it and pull yours out when it's there.
Serve warm with a squeeze of lemon and a drizzle of olive oil. Store any leftovers covered in the refrigerator for up to one week. It reheats beautifully!
Note 1: We tested with homemade chicken stock. If you are using store bought stock or bouillon cubes, they can be very salty. Taste your stock before adding additional salt to the recipe.