Add the olive oil to a large skillet over medium-high heat, add the diced red onions and cook for 3-4 minutes.
Add the ground beef to the skillet and cook until browned, about 7-9 minutes.
Once the ground beef is cooked through, drain any grease from the skillet and set it aside.
Add the entire contents of the cans of diced tomatoes, diced tomatoes with green chilies and green chilies to the crock pot.
Drain and rinse the cans of corn, kidney beans and pinto beans, then add them to the crock pot.
Prepare the taco seasoning by combining all of the spices in a small bowl.
Add the cooked ground beef with onions and taco seasoning to the crock pot.
Stir to combine all of the ingredients.
Cook on high for 4-5 hours or on low for 8-10 hours.
The nutritional information provided is for one bowl of soup and does not include the optional toppings.
To make the soup vegetarian, substitute meatless crumbles or soy chorizo for the ground beef.
To freeze the soup, place it in freezer-safe plastic bags or plastic containers and place in the freezer for up to 6 months. Be sure to leave 1 inch of space in the container for the soup to expand in the freezer.
To reheat the soup from the freezer, add it back to a crockpot set to low for 2 hours, or add it to a large pot on the stove over medium heat and simmer for 20-30 minutes, or until completely thawed and heated through.