3 tablespoons butter
1 onion, chopped
2 (10 ounce) packages chopped frozen broccoli, thawed
1 (10.75 ounce) can condensed cream of mushroom soup
1 cup shredded sharp Cheddar cheese
1 cup mayonnaise
2 eggs, beaten
1/2 teaspoon garlic salt
1/4 teaspoon ground black pepper
1/2 teaspoon seasoned salt
1 1/2 teaspoons lemon juice
12 buttery round crackers, crushed fine
2 tablespoons butter