– unsalted butter, for greasing baking dish – 1 lb. (0.4 kg) French green beans or haricots verts, trimmed and cut into 2-inch lengthss – 2 cans condensed cream of mushroom soup – 3/4 cup half and half – 1 teaspoon garlic powder – 1/2 teaspoon kosher salt – 1/2 teaspoon ground black pepper – 1/2 lb. (0.2 kg) ham, diced – 1/2 cup diced onion – 2 1/2 cups shredded cheddar cheese – 1 1/2 cups canned French fried onions