Easy Chicken Tortilla Soup

INGREDIENTS :
3 tablespoons cooking oil
1 tablespoon dried oregano
2 teaspoons ground cumin
1 teaspoon ground coriander
1 teaspoon ancho chili powder (any chili powder may be substituted)
¼ teaspoon ground red pepper
1 large onion, chopped
4 large cloves garlic
48 ounces canned chicken stock
28 ounces canned crushed tomatoes
2½ teaspoons salt
6 (6-inch) corn tortillas, divided
1½ pounds roasted or rotisserie chicken, cut into chunks or shredded
¼ cup lightly-packed cilantro leaves, roughly chopped
salt and pepper to taste
Optional garnish/toppings: Serve with lime wedges, sliced/diced avocado, sour cream, greek yogurt, shredded cheese, crushed tortilla chips, additional chopped fresh cilantro.

DIRECTIONS :
-In a large heavy pot, heat the oil over medium heat.
-Add herbs and spices (oregano, cumin, coriander, chili powder, red pepper) stir to toast, until fragrant, about 30 seconds.
-Add onion, cook, stirring for about 3 minutes. Grate garlic directly into pot, continue to cook, stirring, for another 2 minutes.
-Add stock, crushed tomatoes, and salt. Bring to a simmer.
-Halve 2 of the corn tortillas, then cut into strips, add to stock. Cook uncovered, stirring occasionally, for at least 25 minutes.
-Add the chicken and reduce heat to medium-low.
-Halve remaining corn tortillas, then cut into strips. Heat a skillet over medium heat. Toss tortilla strips in warm pan to toast, about 3-5 minutes. Be watchful to avoid burning. Just before serving, stir toasted strips into soup.
-Salt and pepper to taste. Serve with optional garnish or toppings.