Spicy Coney-Style Chili Spud

1. Make the chili sauce: Heat olive oil in a large Dutch oven over medium heat. Stir in onions and garlic, and saute, stirring frequently, until soft and translucent, about 3 minutes. Add ground beef and lamb and stir to break up meat. Season generously with salt and pepper, and saute, stirring frequently, until meat browns, about 10 minutes. Stir in chili powder, cocoa powder, cumin, allspice, cloves and cinnamon. Sauté over medium-high heat until fragrant and most of the liquid evaporates, about 5 minutes. Stir in ½ cup tomato paste and cook 1 minute more. Add beef broth, balsamic vinegar and Worcestershire sauce, and stir to combine. Simmer over low heat until mixture is thick and glossy but not completely dry, 35-40 minutes. 2. Meanwhile, bring a large pot of salted water to a low boil. Add potatoes and simmer until they almost cooked through but still firm when pierced with a knife, 15-20 minutes. Transfer potatoes to a towel to drain. (This can be done up to 1 day ahead.) 3. Heat grill to high and prepare for indirect cooking. If you’re using a charcoal grill, once the coals are white hot, bank them on one side to create two cooking zones. If you’re using a gas grill, use all the burners to heat the grill to high, then turn off one side of the burners before grilling. 4. Brush potatoes with olive oil, season with salt and pepper, and wrap tightly in aluminum foil. Place foil packets on unlit side of grill and cover. Cook, turning halfway through, until potatoes are tender at the center and easily pierced with a knife, 35-40 minutes. 5. To serve, split potatoes and fluff flesh with a fork. Spoon ½ cup chili sauce over each. Top with feta and mint, and season with salt and pepper.