Plantain Empanadas

Name: Plantain Empanadas
Ingredients: 1 small Poblano chile, roasted, peeled and seeded; 1/4 teaspoon ground black pepper; 1 cup cold Refried Black Beans, recipe follows, or good-quality canned; 3 ripe plantains, unpeeled; 1 ripe banana, peeled; 1 teaspoon salt; 2 scallions, white and some green parts, thinly sliced; 1/4 cup peanut oil; 1 cup Crema, recipe follows; 1/4 cup grated Anejo, Romano or Feta cheese; 1/4 cup grated Manchego or Feta cheese; Creme Fraiche or sour cream for garnish; 2 cups dried black beans, washed and picked over; 3 tablespoons lard or vegetable oil; 1- 1/2 teaspoons salt; 7-1/2 cups water; 1 large onion