Heat oven to 400° F. Heat 2 tablespoons of the oil in a medium ovenproof skillet over medium-high heat. Add the onion and ½ teaspoon salt and cook, stirring frequently, until beginning to brown, 6 to 7 minutes. Add the beef and cook, breaking it up with a spoon, until no longer pink, 6 to 8 minutes. Add the canned tomatoes (with their juices) and cook until slightly thickened, 2 to 3 minutes more.
Prepare the biscuit mix according to the package directions. Drop 8 mounds of the dough onto the meat mixture in the skillet and sprinkle with the Cheddar. Bake until the biscuits are golden and cooked through, 18 to 22 minutes.
Meanwhile, in a medium bowl, combine the fresh tomatoes, shallot, parsley, vinegar, the remaining 2 tablespoons of oil, ½ teaspoon salt, and ¼ teaspoon pepper. Serve with the cheeseburger pie.
Recipe Provided By: RealSimple.com