Heat your oven to 325 degrees Fahrenheit and switch on the convection feature. Line a heavy-duty sheet pan with foil; then arrange the big racks of ribs on it.
Place the ribs in your oven, and slow-roast them for 2-1/2 hours or until a rib bone turns easily when rotated. If you like your ribs to have a cooked-on glaze, baste them repeatedly with your preferred sauce during the last hour of cooking.
Alternatively, glaze them at the end of their cooking time; then increase the oven temperature to 500 degrees Fahrenheit for five to eight minutes, until the glaze is caramelized.