Tomatillo Sauce

1. Heat oil in a large saucepan over medium heat. Add the onions and garlic and cook, stirring occasionally, until softened, about 5 minutes. Add the tomatillos, serrano chilies, sugar, salt, cumin and 1 cup water; bring to a boil, then reduce the heat to medium-low and simmer until tomatillos are softened, about 8 minutes. Transfer and, working in batches, place the mixture in a blender and purée until completely smooth. Set aside.

Filling

1. Place chicken breasts in a saucepan with garlic, add water to cover (about 4 cups). Bring to a boil over high heat, reduce the heat to medium, cover and simmer until the chicken is cooked through, 20 to 25 minutes. Let cool and drain. Once the chicken is cool enough to handle, shred the meat with your fingers. Sautée onion, cumin, smoked paprika, and salt until onions are soft. Add shredded chicken to the saucepan with chopped cilantro and shredded cheese. Mix one cup of the tomatillo sauce into the chicken mixture.

Assembling

1. Preheat an oven to 375 degrees.
2. Spread 3/4 cup of the tomatillo sauce on the bottom of both a 9 x 13-inch baking dish and a 7 x 11-inch baking dish.
3. Pour oil into a small bowl or ramekin. Using a pastry brush, brush both sides of each tortilla with oil, stack tortillas on a plate and microwave until hot, about 2 minutes.
4. Using your fingers, dip each tortilla briefly in the warm sauce, place on a plate, and spoon about 1/3 cup of the filling near one edge of each tortilla. Gently roll tortillas tightly and place seam side down in the baking dish.
5. Cover with remaining sauce. Sprinkle the cheese evenly over enchiladas. Bake until sauce is hot and bubbling and cheese is melted, about 20 minutes. Remove enchiladas from the oven and sprinkle with smoked paprika; top with lime crema and garnish with lime wedges and guacamole.