Heat oil in a large skillet over medium heat; cook and stir potatoes, onion, and garlic in the hot oil until onion is softened, about 7 minutes. Add ground beef, seasoned salt, and garlic salt; cook and stir until ground beef is browned and crumbly, 10 to 15 minutes.
Blend chipotle peppers in adobo sauce and water in a blender until sauce is smooth. Pour sauce into ground beef mixture; cook and stir until potatoes are tender, 10 to 15 more minutes.
Layer each tostada with chipotle beef, sour cream, and Mexican cheese blend.
