Toast the coriander, black peppercorns, cumin, brown mustard, cloves and cinnamon stick in a dry cast-iron skillet until fragrant, about 3 minutes (see Cook's Note). Grind the toasted spices along with the cardamom pods, nutmeg and red pepper flakes in a spice grinder until fine, about 1 minute.
Transfer roughly two-thirds of the spice mixture (about 2 tablespoons plus 2 1/2 teaspoons), the yogurt, 1 teaspoon of the salt and the turkey thighs to a 1-gallon zip-top bag. Seal the bag, squish to fully coat the thighs and refrigerate for 1 to 3 hours.
Place a 12-inch saute pan over medium-high heat for 2 minutes. Add the canola oil and when shimmering, add the onion and the remaining 2 teaspoons of salt. Cook, stirring occasionally, until the onion begins to brown around the edges, about 8 minutes.
Reduce the heat to low and stir in the ginger, garlic and chiles. Continue to cook, stirring occasionally, until the onion is evenly brown, 7 to 8 minutes more. Add the remaining spice mixture and the tomatoes and cook until reduced and darkened in color, 15 to 20 minutes, stirring every 5 minutes. Stir in the coconut milk and lime juice. Kill the heat and cover to keep warm.
Park a grill pan over medium heat for 5 minutes, then lightly brush with oil. Remove the turkey from the bag, keeping as much yogurt on the meat as possible, and grill until the yogurt is well-charred, approximately 5 minutes per side. Remove the thighs from the heat and rest for 5 minutes before cutting into bite-sized pieces.
Add the turkey pieces to the sauce and simmer over medium-low heat, stirring occasionally, until cooked through, about 20 minutes, taking care to not let the sauce boil as the yogurt may curdle.
To serve, spoon over basmati or jasmine rice and garnish with fresh mint and cilantro.
Alternatively, toast your spices in your air-popper popcorn machine. Just load with the spices, cover the opening with cheesecloth, secure with a rubber band and toast until fragrant, about 30 seconds.