1 Saute the onion and garlic in the bacon drippings or lard in a medium-size saucepan.
2 Add the stock, chiles and comino and simmer until the chiles are tender, about 30 minutes.
3 Ladle the soup into bowls or mugs and top each bowl with some of the grated cheese. Divide about half of the tostados evenly among the servings. Heat the bowls under the broiler for about 5 minutes to melt the cheese.
4 Sprinkle a few more tostados on each.