Mix refried beans, pinto beans, Rotel tomato's, cheese (I leave a little cheese to add to the top before I bake) and place in an 8x8 baking dish.
Bake at 350 for 20-30 minutes ot until heated thru.
After cooling slightly, put a layer of sour cream (depending on taste, I like a little thicker layer myself) followed by the chopped onion and if you choose, the jalapeno's (I put the jalapeno's on top so people can eat around them if they want).
Serve with dip size Fritos or Tortilla chips.
(I have used this same recipe with flour tortillas for simple bean burritos at a childs birthday party. I just used mild Rotel and nixed the jalapeno's).