Preheat oven to 400 degrees.
Halve and deseed bell peppers. Arrange all six halves in 9x13 casserole dish and drizzle with olive oil. Roast in preheated oven for 20 minutes; then remove from oven and set aside.
While peppers are roasting, heat skillet to medium high heat and cook ground beef. If using ground turkey, drizzle pan with 1 tbsp. olive oil before adding turkey to the pan.
Once ground meat is cooked through, reduce heat to low. Add beans, taco seasoning and water to the skillet. Return to simmer and cook for about ten minutes, or until peppers are finished roasting.
Pour ground meat and bean mixture over peppers in an even fashion. You do not need to worry about the mixture staying evenly in each pepper - simply pour over all peppers.
Top with shredded cheese and return to 400 degree oven for 10 more minutes, or until cheese is melted and lightly browned.
Serve with sour cream, avocados and/or tortilla chips.