Preheat grill for medium heat and lightly oil grate.
Heat oil in a saucepan over medium heat. Saute minced onion for about 5 minutes, or until caramelized. Stir in honey, mustard, and vinegar. Season with crushed red pepper, Cajun seasoning, salt, and black pepper. Reduce heat, and simmer 5 minutes, stirring occasionally. Remove from heat, and set aside.
Generously sprinkle ribs with salt and pepper on both sides. Place ribs on grill rack, cover, and open vents halfway. Cook for 35 minutes. Turn ribs once, making sure they are not being over-cooked. Brush tops of ribs with sauce, and cook covered for 5 to 10 minutes Turn ribs over, cover, and cook for another 5 to 10 minutes. Remove ribs from grill. Heat remaining sauce, and serve as a dipping or mopping sauce.
