Warm the refried beans in a small sauce pan over medium heat, while stirring. Loosen with 1-2 tbsp of water if needed to achieve a creamy consistency. Cover, keep warm, and set aside.
Heat up a 1/4 inch of oil in small skillet over medium high heat. When hot and shimmery, add in a corn tortilla and fry for 2 minutes, or until golden and crisp, flipping once. Let drain on paper towels or a wire rack.
Build the tostada: lay out both tostada shells and divide the refried beans on top, using the back of spoon to spread evenly. Top each tostada evenly with the protein, then add on the lettuce, sour cream, tomatoes, onions, queso fresco, and cilantro. Enjoy!
Notes
Estimated nutrition assumes chicken breast as your protein.