Pre heat oven to 375F.
Put white onions and potatoes on the bottom of your baking/roasting pan.
Put pork ribs on the veggies, meat side up.
Tightly wrap the pan with aluminum foil and cook for 1 hour and 15 minutes.
Take pork ribs out of the oven and brush with BBQ sauce on both sides. Return the pan to the oven, uncover, and cook for 10 minutes.
Baste the ribs again and cook for another 10 minutes.
Check for doneness. If the ribs still not cook thoroughly, return it to the oven for another 15 minutes or so. The ribs should have that burnished red color on the surface when done cooking.
Let the ribs rest for 10 minutes. Serve hot with grilled white onions and potatoes, and BBQ sauce on the side.