a meat grinder; 6 koobideh swords or flat shish kebab skewers
For the basting sauce: Add the honey, butter, coriander, cumin, salt, cinnamon, pepper and saffron to a small saucepan over low heat. Let cook 5 minutes, then remove from the heat and set aside.
For the yogurt sauce: Combine the yogurt, vinegar, mint and garlic in a small bowl. Season to taste with salt.
For the roasted tomatoes: Preheat the broiler.
Quarter the tomatoes, then toss with the olive oil, salt and pepper. Place on a baking sheet and broil, checking occasionally to prevent burning, about 7 minutes, then turn over the tomatoes and roast until lightly charred, another 7 to 8 minutes. Set aside.
For the pickled onions: Add the onions, vinegar, salt, sugar and 1 cup water to a small saucepan. Bring to a simmer, stirring to dissolve the sugar, then remove from the heat and set aside.
For the meat: Grate the onion on the largest holes of a box grater and mix into the ground meat along with the salt. Shape the meat into 6 cigar shapes on koobideh swords or flat shish kebab skewers.
Heat a grill or grill pan over high heat. Grill the kebabs, basting with the saffron sauce occasionally, until charred on the outside and cooked through, about 5 minutes per side.
To serve: Preheat the oven to 300 degrees F.
Warm the tortillas in a pan in the oven for 5 minutes.
Spread a heaping spoonful of yogurt sauce on a tortilla. Add the meat, roasted tomatoes and pickled onions. Garnish with torn herbs.