Heat the olive oil in a large pot over medium heat.
Add the onions and cook for approximately 5 minutes, stirring frequently.
Add the garlic to the pot and cook another 1-2 minutes, stirring frequently.
Raise the heat to medium-high and add the ground turkey, chili powder, cumin and crushed red pepper (if using) to the pot.
Stir to mix well and break up the ground turkey with a wooden spoon or spatula. Cook approximately 5 – 7 minutes until it is browned, stirring frequently.
Add the chopped tomatoes, chicken broth, black beans and corn to the pot. Raise the heat to high and stir the soup well to combine all of the ingredients.
When the soup comes to a boil, lower the heat to medium-low, cover the pot and simmer the soup for at least 20 – 25 minutes to let all those flavors develop and come together.
Stir the taco soup occasionally and keep it at a simmer. If it’s boiling too vigorously, lower the heat a bit.
Top the soup with sour cream, shredded cheese, chopped cilantro, tortilla chips or the toppings of your choice.