In a large pot over low heat add in the olive oil and caramelize the onions and garlic well, about 45 minutes.
Next, add in the tomatoes, chile, and chicken stock and simmer over low heat for about 25-30 minutes.
Remove the chile and puree the soup until completely smooth. Return the soup back to the pot along with the chile and season with salt and pepper.
Serve the soup with assorted optional toppings.
Notes
Chef Notes:
Make-Ahead: You can make this soup up to 2 days ahead of time. Be sure to keep the toppings separate.
How to Store: Cover the soup, separate from the toppings, and keep in the refrigerator for up to 7 days. Freeze the soup covered, separate from the toppings, for up to 3 months. Thaw in the refrigerator for 1 day before reheating.
How to Reheat: Add the desired amount to a small saucepot and heat over low heat until hot. You may need to readjust the seasonings with salt and pepper.
When making in the summertime, replace the canned tomatoes with fresh tomatoes.
If you do not want to fry tortilla strips, feel free to use tortilla chips.