Step 1

In a medium bowl, combine the beef, sherry, soy sauce and oil. Let stand at room temperature while preparing the spice mix and the grill.

Step 2

In a small skillet over medium-low, toast the cumin, fennel and Sichuan peppercorns until fragrant, about 2 minutes. Transfer to a spice grinder and add the pepper flakes. Process until coarsely ground, about 10 seconds. Transfer to a small bowl and stir in 1¾ teaspoons salt. Measure out 1 tablespoon of the mix and set aside to use as garnish.

Step 3

Prepare a charcoal or gas grill for direct, high-heat cooking. For a charcoal grill, ignite a large chimney of coals and let burn until lightly ashed over, then distribute the coals evenly over one side of the grill bed; open the bottom grill vents and the lid vent. For a gas grill, turn all burners to high. Heat the grill, covered, for 10 to 15 minutes, then clean and oil the cooking grate.

Step 4

While the grill heats, thread the beef onto ten 8- to 10-inch metal skewers, evenly dividing the meat and pushing the pieces together. Sprinkle the remaining spice mixture evenly over both sides of the meat, patting gently to adhere.

Step 5

Grill until lightly charred, 2 to 3 minutes, then flip and grill until the second sides are lightly charred, another 2 minutes. Transfer to a serving platter, sprinkling both sides of the skewers with the reserved spice mix, then drizzle with chili oil (if using).

Step 6

Oven-Cooking Method: Follow the recipe through making and portioning the spice mix. Heat broiler with a rack about 4 inches from the element. Line a rimmed baking sheet with foil, then set a wire rack in the baking sheet. While the broiler heats, thread the beef onto ten 8- to 10-inch metal skewers, evenly dividing the meat. Sprinkle the remaining spice mix evenly over both sides of the meat, patting gently to adhere. Evenly space the skewers on the rack and broil until well browned, 2 to 3 minutes, then flip each skewer and grill until the second sides are well browned, another 2 to 3 minutes. Transfer to a serving platter, sprinkling both sides of the skewers with the reserved spice mix, then drizzle with chili oil.