In a large fry pan warm your olive oil & onions over medium heat until your onions really start cooking. Then add your stew meat and fry until browned.
Add your 3Tbsp. of flour over browned meat and let the meat get a crisp on the edges.. Then add 3 cups of water and let cook on medium heat until it thickens the gravy.
Add your cubed potatoes, mixed veggies and diced tomatoes when it comes to a boil reduce heat and let it simmer 1 1/2 hours, stirring occasionally. Salt and pepper as needed. Serve with biscuits, and over rice, if desired.