Oven-Baked BBQ Ribs

Step 1
Preheat the oven to 350 degrees F (175 degrees C). Split ribs down the center between the bones.

Step 2
Mix onions, ketchup, water, vinegar, brown sugar, Worcestershire sauce, mustard powder, and salt together in a bowl. Set aside 1/2 of the sauce for basting.

Step 3
Heat oil in a large skillet over medium-high heat. Working in several batches, add ribs and sear until browned, 4 to 5 minutes per batch.

Step 4
Transfer ribs to two baking pans and arrange in a single layer. Pour remaining BBQ sauce over ribs.

Step 5
Bake in the preheated oven for 3 hours. Turn and baste every 20 minutes with the reserved sauce, using all sauce after 2 hours of cooking. For the last hour, continue to turn ribs every 20 minutes, basting with the sauce in the pan. Meat should easily pull away from the bone, and an instant-read thermometer inserted into the center should read at least 145 degrees F (63 degrees C).