Preheat the grill for 20-30 minutes on medium-high heat with the lid down.
For the wet base, combine mustard and vinegar. Rub the ribs down with the mixture, thoroughly covering the meat.
For the dry rub, combine all the spices. Generously season the ribs with the spice mix and rub down until nicely coated. Save some of the dry rub for later.
Flip over the ribs and repeat the process of applying the wet base first, then the dry rub.
Place ribs on a large piece of aluminium foil with the shiny side up. Depending on the fat content of your ribs, you can add some butter on top. First pull up the long sides of the foil, then roll up the edges and secure tightly to avoid leaking. Repeat wrapping with another piece of aluminium foil.
Place wrapped ribs on the grill for 1 hour, lid down, until fully cooked through, flipping every 20 minutes.
When the ribs are ready, remove from the grill. Turn up the grill to the highest temperature.
Carefully remove the foil and watch out for the steam. Transfer to a cutting board and sprinkle with some more dry rub. Place back on the grill and close the lid. Grill for 2-5 more minutes if it’s already crispy or 10 minutes if it needs more crisping up.
Remove from the grill allow to cool for 5-10 minutes before serving.
If you like things spicy, feel free to add more chili powder to the dry rub mixture.
If you have leftovers from the dry rub, save it for your next cookout!