Preheat your oven to 400°F (200°C).

Lightly brush both sides of each corn tortilla with olive oil and place them on a baking sheet in a single layer.

Bake the tortillas for 8-10 minutes, flipping them halfway through, until they are crisp and golden brown.

Spread a layer of refried beans evenly onto each baked tortilla.

Add a layer of cooked ground beef or shredded chicken on top of the beans.

Sprinkle shredded cheddar cheese over the meat layer.

Top each tostada with shredded lettuce and diced tomatoes.

Finish with a dollop of sour cream and guacamole on each tostada.

If desired, garnish with sliced black olives and jalapeño slices.

Serve immediately and enjoy!