In a large cast iron skillet brown hamburger along with onions and garlic until meat is cooked through. Drain any grease
Sprinkle meat with flour and stir to incorporate. Cook for an additional minute.
Add in tomatoes, vegetables, Worcestershire sauce, beef broth and seasonings.
Stir and simmer until it thickens into a nice gravy consistency.
Top with warm mashed potatoes and smooth to cover.
Place under broiler for a few minutes to crisp up and brown potatoes
Notes
If you don't have leftover mashed potatoes, use this recipe to make some.Notes: If meat mixture and potatoes are cold. Cook in a 400 degrees F oven for about 20 minutes or until heated through and then place under broiler if needed to brown potatoes.