Heat a grill or cast-iron skillet on high until very very hot.
Combine the beef, tomato powder, tomato paste, oil, salt, pepper, garlic, and onion in a mixing bowl and mix very gently just to combine. Scoop into patties, without pressing or mashing (you want some “air space” inside that patty, so don’t squish it flat).
Carefully place the burgers on the grill or into the skillet and cook on the first side for 3 to 6 minutes. Turn over and cook for 2 to 6 minutes longer, until nicely seared and the center is cooked to your preferred doneness. Toast the buns or rolls lightly on the grill while the burgers cook, if desired. Serve immediately with Homemade Ketchup if desired.