How to Make It
Toss together cumin seeds; Sichuan pepper, if desired; chile flakes; and 2 crushed garlic cloves. Cut lamb into 3- x 3/4-inch strips. Toss lamb strips with cumin mixture in a large bowl; cover and chill at least 1 hour and up to 24 hours. Follow instructions for grinding lamb using the grinding technique here, gently folding cold cooked rice into coarsely ground lamb before regrinding in step 5 and omitting step 6 (do not knead).
Preheat oven to 450°F with oven racks in upper third and lower third of oven. Coat a 13- x 9-inch broiler-safe rimmed baking sheet or baking dish with 1 tablespoon canola oil, and line bottom of baking sheet with parchment paper.
Stir together cilantro, cream, parsley, egg yolks, olive oil, and 4 1/2 teaspoons salt in a large bowl. Crumble ground lamb into bowl; add panko and 1/4 cup white sesame seeds. Mix with hands until thoroughly incorporated.
With oiled hands, gently roll mixture into 28 golf ball–size (about 1 1/2-inch) meatballs. Place on prepared baking sheet in a snug grid formation with meatballs touching on all sides. Sprinkle black sesame seeds and remaining 1 tablespoon white sesame seeds over top.
Place bell peppers, onions, jalapeños, ginger, remaining 2 garlic cloves, remaining 2 tablespoons canola oil, and remaining 2 teaspoons salt on a baking sheet. Toss to coat, and spread in an even layer.
Place vegetable mixture in the lower third of preheated oven and meatballs in the upper third. Roast until vegetables are crisp-tender, about 9 minutes; remove from oven. Continue baking meatballs until slightly firm, about 3 minutes. Remove meatballs, and turn on broiler to low. Broil meatballs in upper third of preheated oven until crusty and golden brown, about 8 minutes. Remove meatballs, and let cool on baking sheet 5 minutes before serving. While meatballs cool, stir vegetable mixture, and place in upper third of oven. Broil until slightly charred in spots, 5 to 8 minutes. Serve meatballs with rice and roasted vegetables topped with cilantro.