Step 1In a skillet, toast the cumin, black peppercorns, 2 tablespoons Sichuan peppercorns, 4 dried chiles, 1 ½ teaspoons fennel seeds and 2 star anise pods over moderate heat, stirring until fragrant, about 3 minutes. Let cool, then finely grind. Transfer to a bowl and mix with the onion and garlic powders and ginger. This can be stored in a sealed container at room temperature overnight.
Step 2Heat the oven to 400 degrees. Set 2 wire racks over each of 2 rimmed baking sheets. Lightly brush the lamb all over with oil and then with the soy sauce. Rub the spice mixture all over the lamb. In a skillet, heat the 2 tablespoons of oil over medium-high heat. In batches, sear the racks until browned on both sides, about 2 minutes per batch. Transfer to the baking sheets.
Step 3Roast the lamb until an instant-read thermometer inserted in the center registers 135 degrees, 25 to 45 minutes, depending on the size of the racks. Let rest for 15 minutes.
Step 4In a saucepan, combine the veal stock, ginger, garlic, doubanjiang, cinnamon, sugar, cloves, cardamom, and the remaining Sichuan peppercorns, dried chile, star anise and fennel seeds. Simmer over moderate heat until reduced to 1 cup, 15 to 30 minutes. Whisk in the butter and season with ½ teaspoon salt, or to taste; strain into a bowl and keep warm. The sauce can be made in advance, refrigerated overnight and reheated before serving.
Step 5In a shallow bowl, dust the shallot rings with Wondra flour. In a high sided pan, heat 1½ inches of vegetable oil over medium-high heat to 325 degrees. Fry the shallot rings until golden and crisp, about 1 minute. With a slotted spoon, transfer to paper towels to drain.
Step 6Carve the lamb into chops and drizzle with the sauce. Garnish with scallions, sliced red chiles and crispy shallots and serve.