Gradually pour in the chicken broth and water, stirring, until the mixture is smooth.
500 ml chicken broth, 250 ml water
Add the tomato paste, oregano, cumin, and salt.
170 g tomato paste, 1 teaspoon oregano, 2 teaspoons cumin, 0.5 teaspoon salt
Stir until the sauce is smooth.
Bring to a simmer.
Cover and cook for 10 minutes over low heat.
Take out the portion of sauce meant for the chicken and set it aside.
250 ml red enchilada sauce,
Blend the rest of the sauce until perfectly smooth.
Set the blended sauce aside for assembly.
Shredded Chicken
Return the sauce set aside for the chicken to the saucepan.
Add the water and chicken breasts.
120 ml water, 700 g chicken breasts,
Bring to a simmer.
Cover and cook at a gentle simmer for 30 to 45 minutes, until the chicken shreds easily with a fork.
Shred the chicken right in the sauce using two forks.
Set aside.
Assembly
Preheat the oven to 180°C.
Mix the Monterey Jack and cheddar in a bowl.
340 g Monterey Jack,, 340 g cheddar,
Set the cheese mixture aside.
Pour one third of the blended sauce into the bottom of a 28 x 38 cm baking dish, or two smaller dishes with the same total area.
Lightly grease a heavy-bottomed frying pan with oil.
Oil,
Heat the pan.
Warm a corn tortilla in the pan on both sides until it is pliable enough to roll without breaking.
16 corn tortillas,
Place the warm tortilla in the dish.
Top the tortilla with about 3 tablespoons of shredded chicken in its sauce and 2 tablespoons of the cheese mixture.
Roll the tortilla up tightly.
Place it in the dish, seam side down.
Repeat with the remaining tortillas until the dish is full.
Baking
Spoon the rest of the blended sauce over the enchiladas.
Top with the rest of the cheese mixture.
Bake for 25 to 30 minutes, until the cheese has melted.
Serve hot with your choice of toppings.
Notes
Corn or flour tortillas: this recipe uses corn tortillas, in keeping with Tex-Mex tradition. A flour tortilla, full of gluten, turns gummy and puffy as it cooks in the sauce, whereas a corn tortilla holds its shape. Warming them in a little oil makes them pliable enough to roll without cracking and shields them somewhat from the sauce, which keeps the dish from turning soggy. In Europe, corn tortillas can be found in the international foods aisle.Chili powder: in the United States, “chili powder” is a mild blend of ground ancho chile, cumin, oregano, garlic, and salt. In Europe, a jar labeled “chili” or “ground chili pepper” almost always contains pure hot chili, close to cayenne pepper: 5 tablespoons would make the sauce inedible. Use a Tex-Mex or chili con carne spice blend, or make a mild blend based on sweet paprika. Suggested proportions for this blend: 2.5 tablespoons sweet paprika, 1.75 tablespoons ground cumin, 1 teaspoon garlic powder, 1 teaspoon dried oregano, and just 0.125 to 0.25 teaspoon pure hot chili powder.Corn flour: this means finely ground corn flour, sold as “corn flour,” which thickens the sauce and keeps it gluten-free.Cheese: Monterey Jack is hard to find in Europe. Young Gouda, Havarti, or a mild cheddar make good substitutes.Make ahead: the enchiladas can be assembled in advance and kept in the refrigerator until you're ready to bake them. For a gluten-free version, check that the corn tortillas are certified gluten-free.Homemade sauce has much more flavor than canned. On the side, serve refried black beans, Mexican rice, or cilantro-lime rice. Toppings are up to you; in Tex-Mex cooking, the enchiladas are often sprinkled with thinly sliced onion and fresh cilantro, with sour cream on the side.