Make meatballs: In a small frying pan, toast cumin over medium heat until fragrant, 3 to 5 minutes. Grind in a spice grinder, put 1 tsp. in a medium bowl, and reserve the rest for chutney. Grind coriander and fennel and add to bowl with remaining spices, salt, lamb, and egg. Mix gently. Chill mixture until firm enough to shape, about 15 minutes.
Make chutney: Put all chutney ingredients and reserved cumin in a food processor and whirl until very smooth. Add more lemon juice if you like. Spoon into a serving bowl.
Finish meatballs: With wet hands, form chilled meat into 1-in. balls and set on a baking sheet. Heat oil in a heavy 12-in. nonstick frying pan over medium heat. Fry meatballs until well browned all over, 8 to 10 minutes total. Transfer to paper towels.
Serve meatballs with toothpicks and the chutney.
*For a milder chutney, seed chile before mincing.
Note: Nutritional analysis is per 3-meatball serving with 3 tsp. chutney.