In a large pot, heat the olive oil over medium heat. Add the diced onion and sauté for about 3-4 minutes until translucent.
Stir in the minced garlic and diced red bell pepper and cook for an additional 2-3 minutes until the bell pepper has softened.
Add the ground turkey to the pot and cook, breaking it up with a spoon, until it is browned and cooked through, about 5-7 minutes.
Sprinkle the taco seasoning over the cooked turkey mixture, stirring well to coat all ingredients.
Pour in the chicken or vegetable broth and add the drained black beans, kidney beans, diced tomatoes (with their juice), and corn. Stir everything together and bring to a gentle boil.
Reduce the heat and let the soup simmer for 15-20 minutes, stirring occasionally. Season with salt and pepper to taste.
When ready to serve, ladle the soup into bowls and add desired toppings such as shredded cheese, avocado, cilantro, sour cream, or crushed tortilla chips.
Notes
Feel free to customize toppings based on your preference.