Preheat oven to 325 degrees F. Wrap soft tortillas in aluminum foil stacked in two packages. Place tortillas in the hot oven to warm through. Or if using crispy shells, follow heating instructions just before serving.
Meanwhile, heat the oil in a large skillet over medium-high heat. Add the pepper, onion, and garlic, and cook, stirring often until the vegetables are softened and beginning to brown. This should take 5 to 8 minutes.
Add the ground turkey, and cook, breaking it up into small pieces as it becomes opaque, until the turkey is completely cooked – 4 to 6 minutes.
Sprinkle the ground turkey mixture with chili powder, cumin, salt, and chipotle, and stir everything to combine until it’s fragrant, which takes about 30 to 90 seconds.
Add the tomato paste and water and stir until the tomato paste is dissolved into the water and it forms a sauce to coat the turkey mixture.
Serve the turkey in the warm tortillas (or crispy taco shells) with cheese and top with desired toppings.
