In a large Dutch oven or heavy-bottomed pot over medium heat, add the oil and onion and cook, stirring frequently, until the onion is translucent, about 4-5 minutes. Add the garlic, chili powder, cumin, and paprika and cook, stirring, for 1 minute more, until fragrant.

Stir in the chicken broth, enchilada sauce, and green chilies, then add the chicken breasts and bring the soup to a low boil.

Reduce the heat to medium-low, cover, and simmer for 20-25 minutes, until the chicken is cooked through (165°F in the thickest part) and tender.

Transfer the chicken to a bowl. Once it's cool enough to handle, shred it into bite-size pieces with two forks.

While the chicken cools, add the masa harina to a medium bowl, ladle in 2-3 cups of the hot broth from the pot, and whisk until smooth. The mixture will be thick.

Stir the masa harina mixture back into the soup, then add the shredded chicken. Simmer, stirring often, for 5-10 minutes, until the soup has thickened.

Reduce the heat to low, add the shredded cheese, and stir until melted.

Serve warm, topped with tortilla strips and lime wedges.