Heat olive oil in a large soup pot over medium heat. Add the chopped onion and cook until soft and translucent. Stir in the minced garlic and cook for another minute until fragrant.
This step creates a flavorful base for the entire soup. Make sure not to brown the garlic, as it can turn bitter. The onion should become soft and slightly sweet.
Stir in the uncooked rice, cumin, chili powder, and salt. Let the rice toast slightly for about one minute while stirring.
Toasting the rice enhances its flavor and helps it absorb the broth better. The spices will bloom in the warm oil, releasing deeper aromas.
Add the enchilada sauce, chicken broth, diced tomatoes, and black beans. Stir everything together well. Bring the mixture to a gentle boil, then reduce heat to low and cover.
Let the soup simmer for about 20 minutes, or until the rice is tender. Stir occasionally to prevent sticking. The soup will naturally thicken as the rice cooks.
Once the rice is fully cooked, remove the pot from heat. Gradually stir in the shredded cheddar and Monterey Jack cheese until melted and smooth.
Adding cheese off the heat prevents it from becoming grainy. Stir slowly to achieve a creamy, velvety texture throughout the soup.
Ladle the hot soup into bowls. Top with chopped cilantro and crunchy tortilla strips.
The fresh herbs and crispy topping add contrast to the creamy soup. Serve immediately while it’s warm and cheesy.