For a speedier preparation, replace the guajillo sauce with 8 ounces of store-bought enchilada sauce.
Heat the oil in a large (4-quart) saucepan over medium. One or 2 at a time, fry the chiles until they’re aromatic and change color (they’ll lighten a little on the inside and brown on the outside), 10 seconds or so on each side. Remove to a bowl, cover with hot tap water, weight with a plate to keep them submerged and rehydrate for about 20 minutes. Set the pan aside.
Scoop the chiles into a blender jar, along with 2/3 cup of the soaking water.
Add the garlic, oregano and pepper and blend to a smooth puree. (If the mixture won’t move through the blender blades, add a little more of the soaking liquid to loosen it up.)
Return the oily pan to medium-high heat. When hot, set a medium-mesh strainer over the pan and press the chile mixture through. Discard the skins and seeds left in the strainer. Cook, stirring nearly constantly, until the consistency of tomato paste, about 4 minutes. Pour in 3/4 cup water, reduce the heat to medium-low and simmer, stirring regularly, until the sauce takes on a medium consistency, about 5 minutes. Taste and season highly with salt, usually about 1 teaspoon; adding about ½ teaspoon sugar will bring out the natural fruitiness of the chile and balance the heat a little.
Add the kale, beans and masa dumplings if you are using them (recipe here) to the sauce all at once, tossing to coat with the guajillo sauce. Cook, stirring carefully, until the kale is tender and the dumplings are cooked through, about 12 minutes. Transfer the mixture to a warm serving bowl. Sprinkle the queso fresco on top and you’re ready to serve.