In a medium bowl, whisk sugar into jalapeno liquid until dissolved. Cut 4 slices tomato and reserve for burgers. Cut remaining tomato into 3/4-inch pieces and add to dressing. Stir in cucumber and onion. Season with salt and pepper.
In another medium bowl, combine beef and chili powder. Form into 4 patties and season with salt and pepper. In a large nonstick skillet, cook burgers over medium-high until cooked through, about 8 minutes total, flipping once. Serve burgers on buns with tomato slices, pickled jalapenos, and shredded lettuce, alongside cucumber salad.
$1.97 per serving