My friend Perla, a native Mexican, showed me how to make these tostadas. She even showed me how to make the refried beans from pintos. Just saute them in oil and smash them. When I was single I used to make them as a meals, although they are traditionally a snack.
Tostadas about 10
mozarella cheese about 1.5 cups
fresh chopped cilantro
red onion, finley diced
refried beans, almost 1 can
Smear the tostadas with beans and sprinkle with cheese. Toast in the oven until cheese melts (which also is long enough to crisp the tostadas. When they are heated, pull them out and top with cilantro and onion. I also put a little black olive on mine...