In a large skillet, cook the ground beef over medium-high heat until browned, breaking it apart with a spatula. Drain excess grease.
Add the finely chopped onion, garlic powder, onion powder, paprika, salt, and black pepper to the skillet. Stir well and cook for about 3-4 minutes, until the onion softens.
Remove from heat and mix in the ketchup and mustard. Set aside to cool slightly.
In a small bowl, combine the mayonnaise and a splash of ketchup to create a special sauce.
Prepare the taco shells according to package instructions (if applicable).
To assemble the tacos, spoon a portion of the beef mixture into each taco shell.
Top each taco with shredded lettuce, diced tomatoes, and a generous sprinkle of shredded cheddar cheese.
Drizzle a little of the special sauce on top and add pickles if desired.
Serve immediately, or warm, for an extra delicious bite!