LAMB: Preheat grill or oven to 375F. Rub each rack all over with olive oil. Brush or spread meat side of each rack with mint jelly and season on top of that with salt and pepper. Transfer racks to hot grill, pepper side down. Grill with lid closed about 8 minutes, then turn 90 degrees and grill another 8-10 minutes until desired doneness.
CHUTNEY: Heat olive oil in a small saucepan over medium-high heat. Add onions and celery and saute until soft. Add garlic and saute until fragrant. Add remaining ingredients and cook over medium-low heat for 15 minutes, stirring often, until thick.