Place stew meat, 1/2 cup water, salt and pepper in crockpot.
Drain juice from tomatoes into a measuring cup.
Add tomatoes, garlic, onions, and potatoes to crockpot.
Blend juice from tomatoes and enough water to equal 2 cups of liquid. Add cumin, oregano, and chili powder and flour into tomato juice mixture and mix well. Add to crockpot. Add salt and pepper to taste.
Cook on low for 6-7 hours until sauce is thickened and meat and veggies are tender.
Just before serving, warm your tortillas and enjoy.