Combine chicken breast, onion and enough water to cover in a medium saucepan over medium heat. Boil for 25 minutes or until chicken is cooked through. Remove from heat and let cool. Discard onion. Reserve broth for another recipe if desired. Remove skin and bones from cooked chicken. Shred chicken meat with two forks, season with salt and pepper. Set aside.
Heat 1-inch deep oil in a large skillet over medium heat. Carefully add sopes 1-2 at a time and cook 4 minutes on each side or until golden brown and cooked through. Transfer to a paper towel lined plate to drain excess oil. Repeat with remaining sopes.
Spread 2-3 tablespoons warm beans on each sope. Top with chicken, lettuce, tomato, a few radish slices, serrano chile slices, a drizzle of crema and a sprinkle of cheese. Serve.
Servings 6