01 -
Preheat the oven to 350°F (175°C). Lightly grease a 9x13-inch baking dish.
02 -
In a large skillet, melt 2 tablespoons butter over medium heat. Sauté the chopped onion for 3–4 minutes until translucent. Add garlic and cook for 1 more minute.
03 -
In a large mixing bowl, combine broccoli, sautéed onion and garlic, soup, sour cream, milk, eggs, mustard, salt, and pepper. Stir in 1½ cups of the cheddar cheese.
04 -
Transfer the mixture into the prepared baking dish and spread evenly. Top with the remaining ½ cup of cheddar cheese.
05 -
In a small bowl, mix crushed crackers with olive oil or melted butter. Sprinkle evenly over the casserole.
06 -
Bake for 30 minutes, or until bubbly and golden brown on top. Let rest 5 minutes before serving.