Heat a skillet over medium heat. Add an inch of canola oil. Once oil is hot (about 350 degrees F), cook corn tortillas flipping after first side is browned and crispy. Remove tortillas to a paper towel lined plate and lightly salt them. Set aside.
Heat another skillet over medium heat. Add olive oil. Add ground beef and break apart with a wooden spoon, cooking until no longer pink. Add salt, pepper, Worcestershire sauce, ketchup and mustard. Stir until well combined and cook another minute to heat the sauce through.
To assemble the tostadas: top each corn tortilla with desired amount of ground beef. Sprinkle with cheddar and melt in the microwave for 30 seconds, if desired. Top with shredded lettuce, tomatoes and pickles.
