Cheddar-Onion Hot Dip

2 cups shredded cheddar cheese
1 large onion, chopped
2 cups Hellman's mayonnaise (I've tried others and they don't work the same)

Mix all in an oven safe baking dish.
Bake at 400 for 25 to 30 minutes.
Serve with crackers.
Yum !!!!