1 tablespoon + ½ teaspoon fajita seasoning, divided
Pinch of chili flakes
⅓ teaspoon onion powder
¾ teaspoon garlic powder, divided
salt, to taste
pepper, to taste
½ cup mayonnaise
¼ cup sour cream
1 tablespoon fresh coriander, finely chopped
Juice of ½ lime
1 tablespoon cooking oil
1 large onion, sliced
2 red bell peppers, sliced
6 slices cheddar cheese
6 burger buns
1 cup lettuce leaves
Directions
In a large bowl, combine the ground beef, egg, 1 tablespoon of fajita seasoning, chili flakes, onion powder, ½ teaspoon of garlic powder, salt, and pepper.
Form the beef patties into round shapes, making 6 in total, with dimples in the middle. Chill the beef patties in the fridge for at least 30 minutes.
To make the sauce, mix together the mayonnaise and sour cream with ¼ teaspoon of garlic powder, the chopped fresh coriander, the lime juice, and ½ teaspoon of fajita seasoning.
Heat up the cooking oil in a large pan to a medium heat.
Add the sliced onion and bell peppers, and saute for 15 minutes or until caramelized. Set aside.
Heat up a lightly greased cast iron pan to a medium-high heat, then add the beef patties, as many as will reasonably fit. Don't overcrowd the pan.
Cook for 3-4 minutes each side until the patties are browned on the outside and just cooked through.
Top the burgers with sliced cheddar cheese and allow it to melt about 1-2 minutes before the burgers are done cooking.
Serve the buns by layering a spoonful of sauce followed by lettuce, the cooked beef patty, a spoonful or two of the cooked onions and peppers, and the top of the burger bun, similarly slathered with a spoonful of sauce.