In a large skillet, heat the olive oil over medium heat. Add the diced onion and sauté for about 3-4 minutes until translucent.
Add the minced garlic and cook for an additional minute, stirring frequently to prevent burning.
Increase the heat to medium-high and add the ground turkey. Cook until browned, breaking it apart with a spatula, about 5-7 minutes.
Stir in the diced bell peppers, oregano, smoked paprika, salt, and pepper. Cook for another 5 minutes until the peppers are tender.
Add the drained diced tomatoes and stir to combine. Cook for an additional 2-3 minutes until heated through.
If using, stir in the cooked quinoa or rice until well mixed and heated.
Remove from heat and garnish with fresh parsley before serving.