Hearty pork spare ribs baked in a rich and flavorful ancho chile sauce are a summertime treat que está para chuparse los dedos (that is, finger-lickin’ good). Barbecue ribs are one of my favorite summertime foods because they remind me so much of my childhood summers when my abuelito would bake ribs in the oven in a homemade sauce, while my abuelita worked on making classic side dishes like refried beans, Mexican rice, and potato salad. Once the ribs were done, we’d pack everything up and head to the park to enjoy our delicious meal under the shade of our favorite tree.
Bring the dried chiles and water to a boil in a medium saucepan over medium-high heat. Cover and reduce heat to low; let simmer for 5 to 7 minutes until the chiles have softened completely. Remove from heat and let cool slightly. Puree the dried chiles and 2 cups of the cooking water with the garlic, cumin, and dried oregano in a blender until smooth; season with salt to taste.
Preheat oven to 350°F.
Season the spare ribs with salt and ground black pepper. Heat the vegetable oil in a cacerola or Dutch oven over medium-high heat. Fry the spare ribs until light golden brown all over. Stir in the chopped onions and serrano chile; saute for about 2 minutes. Pour in the ancho chile sauce and let sauce come to a boil. Remove from heat.
Cover and bake at 350°F for about 2 hours until the pork is tender. Uncover and bake for an additional 15 minutes. Remove from oven.