Heat vegetable oil (1 tablespoon) in a 12-inch skillet. Brown beef (1 pound) until there is no longer any pink. Remove cooked beef to a paper towel-lined plate. Drain skillet of all but 2 tablespoon oil.
Saute onion (1/4 cup) in pan drippings, over medium heat, until translucent. Return cooked beef to skillet. Add the rest of the ingredients and bring the mixture to a simmer. Reduce heat and continue to simmer for 30 minutes. Scoop mixture out over hamburger buns and serve.
Notes
Ground Beef: I use 80/20. Leaner cuts have less flavor and can be a bit drier.
Onion: Yellow onions are my choice. You could also use a white onion which tends to be milder.
Taco Seasoning: Using prepackaged taco seasoning to make this quick and easy. I like to make it kid-friendly by using a mild version.
Salsa: I like mild salsa for this recipe. Again, keeping it kid-friendly!
Worcestershire Sauce: Adds a little richness and depth of flavor.
Apple Cider Vinegar: This adds the necessary little bit of tang and smidge of fruitiness.
Hamburger Buns: Any hamburger bun will work. I like brioche buns because they're rich and a little sweet. My husband likes to use onion buns. The kids like them all!
Brown Sugar: You can use either light or dark brown sugar.