Preheat oven to 350F.
Melt 1 tablespoon butter in large skillet over medium heat. Add corn and saute until corn gets slightly brown. Remove from heat.
In a separate skillet, melt remaining butter, then add both kinds of onions, bell pepper, jalapeno and garlic. Cook until onions are soft. Add this mixture to the corn.
Stir in the monterey jack cheese, mayonnaise, and cayenne pepper. Pour into baking dish and top with shredded cheddar.
Bake for 15 minutes, until top is brown and bubbly. Serve with tortilla chips, corn chips or cut vegetables.