Line a large baking sheet or cutting board with foil (for easy clean-up). Cut ribs into 2-rib sections and lay out on foil.

Combine all rub ingredients and sprinkle over ribs. Use hands to rub into both sides of meat. Set aside.

In a mixing bowl, whisk together ketchup, 3 tablespoons brown sugar, Worcestershire sauce, apple cider vinegar, mustard powder and 3/4 teaspoons salt. Heat pressure cooker to saute function and add oil and onion. Saute for 3-4 minutes, until soft. Add garlic and cook for another 30 seconds, stirring often. Add the ketchup mixture and stir to combine. Add a few ribs at a time and use tongs to gently coat them in sauce. Then arrange ribs standing upright with meat-side facing outward (see blog post for visual).

Secure lid on pressure cooker and set to high pressure for 30 minutes cook time.

When finished, turn pressure cooker off (or remove stovetop pressure cooker from heat) and let naturally release pressure for 15 minutes. Manually release any remaining pressure and then open pot. Place ribs on platter and coat with sauce.

Optional: Arrange cooked ribs meat-side up on baking sheet and broil for charred exterior.