In a large skillet, heat the oil over medium-high heat. Fry the tortillas, two at a time, turning occasionally, until crisp and the edges are lightly browned, 2 to 3 minutes. Transfer to a paper towel-lined plate to drain and cool.
In a small pot, warm the refried beans over medium-low heat, stirring occasionally, until hot, about 6 minutes. Cover and set aside to keep warm.
In the same large skillet used to fry the tortillas, heat the residual oil over medium heat. Add the onion and cook, stirring occasionally, until softened, about 6 minutes.
Add the ground beef, chili powder, salt, cumin, paprika, garlic powder, oregano, and black pepper. Cook, stirring occasionally while breaking up the beef into small crumbles using the back of the spoon, until browned and cooked through, about 8 minutes. Remove from heat.
To assemble, spread about 2 tablespoons of refried beans on each fried tortilla. Top each with about ¼ cup of the seasoned ground beef and any desired toppings.
Notes
Only fry as many tortillas as you need for one meal. This recipe yields 12 crispy tostadas, but feel free to reduce the amount of tortillas you fry depending on how many people you’re serving. That way, your shells will be fresh and crispy.
You can use store-bought tostada shells instead of frying tortillas. Warm them in a 350°F oven or air fryer for 3 to 5 minutes to re-crisp.
Spread refried beans onto fried tortillas first. The beans will help the other toppings “stick” to the tortilla better, making the meal less messy.
Don’t pile the toppings too high. Be generous with the toppings, but don’t pile them too high as they’ll topple right off when you start eating.
Eat tostadas like you would a slice of pizza. If you’ve ever wondered how to eat tostadas, you’ll be happy to know that there’s nothing complicated about it! Just hold it like a slice of pizza and enjoy. Some toppings will inevitably fall off, so I keep a fork nearby to scoop them back onto the tortilla.