Pre-heat your oven to 300F

Mix pure chili powder, cumin, granulated garlic, granulated onion and salt. This is your dry rub.

Remove silver skin from the rib side of the ribs. Insert a knife between the membrane and the rib and lift. Get your fingers under the skin and pull. This is easy sometimes and thoroughly annoying other times. I've never been able to figure out why.

Thoroughly coat the ribs with the dry rub.

Place ribs on a rack on the cookie sheet, place in oven and slow roast until they reach an internal temperature of about 185F. This can take up to 2 1/2 hours depending on the rack. Measure temperature in the thick parts and between the ribs. Don't let the probe touch bone. That will mess up the reading.

While the ribs are cooking prep the sauce.

Add oil to a pan and heat over medium low.

Add the onion, chili powder, cumin, Mexican oregano and salt and cook until the onions are translucent.

Add the garlic and cook another 30 seconds.

Add tomatoes and a splash of chicken stock and simmer around 30-45 minutes, taking care not to let the pot boil dry.

When the ribs have reached 185F or so remove from oven and let cool slightly.

Slice into individual ribs and add to the tomato sauce. Add the cilantro. Simmer ribs in sauce for about 20-30 minutes.