In a very large, high-sided skillet, heat oil over medium-high heat.
Add onion, bell peppers, ground beef and ground turkey. Cook, breaking up the meat, until the turkey is no longer pink and the vegetables are cooked.
Add flour and taco seasoning and stir to combine, continuing to cook for 1-2 minutes or until spices are fragrant.
Stir in water, and reduce heat to medium-low. Continue to simmer over medium-low heat stirring occasionally until water is mostly evaporated. You can keep this at a low simmer, partially covered, until you’re ready to serve — you may need to add more water if it starts to look dry.
Notes
If you use a nonstick skillet, you can probably omit the oil in this recipe.
If you want, use all ground beef or all ground turkey.