Try to buy oxtails that are approximately 2 inches thick and 2 to 4 inches in diameter. Oxtails can often be found in the freezer section of the grocery store; if using frozen oxtails, be sure to thaw them completely before using. You can substitute 1½ teaspoons paprika and 1½ teaspoons finely chopped red pepper flakes for the Aleppo pepper, if desired.
