Heat a large skillet over medium-high heat and coat with cooking spray. In a bowl, combine ground beef, onion, and garlic.
Divide the mixture into 4 equal portions. Form each portion into a loose ball. Place one ball in the skillet and press down firmly with a spatula to create a thin patty slightly smaller than your tortillas.
Top the patty with a tortilla and cook for 7-8 minutes, or until the beef is cooked through. Drain off any excess fat.
Flip the taco and top with cheese slices (optional). Transfer the taco to a baking sheet and place it in the preheated oven to keep warm. Repeat steps 3-5 for the remaining patties.
While the tacos are cooking, whisk together all sauce ingredients in a bowl until smooth.
To assemble the tacos, place each on a plate. Top with shredded lettuce, sliced gherkins, chopped tomatoes, and a drizzle of the sauce. Serve with any remaining salad on the side.
Tips:
For a spicier sauce, add a pinch of cayenne pepper or a few dashes of hot sauce.
You can substitute other vegetables for the lettuce, tomatoes, and gherkins, such as shredded cabbage, sliced avocado, or chopped bell peppers.
Feel free to use your favorite cheese for the tacos.
To make the tacos lower in fat, use ground turkey or chicken instead of beef.