For the pork chops: Season four 1-inch-thick boneless pork chops on both sides with salt, then rub all over with vegetable oil. Sprinkle with your choice of spice rub (recipes follow). Grill over medium-high heat until cooked through and a thermometer inserted into the centers registers 145˚ F, 4 to 5 minutes per side.
To make Sichuan Peppercorn Rub: Pulse 2 tablespoons Sichuan peppercorns in a spice grinder with 4 teaspoons cumin seeds, 2 teaspoons sesame seeds and 1 teaspoon red pepper flakes until cracked. Transfer to a small bowl and mix in 1 teaspoon each Chinese five-spice powder and light brown sugar and 1/2 teaspoon garlic powder.
To make Barbecue Rub: Mix 1 tablespoon each paprika and light brown sugar in a small bowl with 2 teaspoons ancho chile powder, 1 teaspoon ground cumin and 1/2 teaspoon each mustard powder, garlic powder, onion powder and pepper.
To make Fennel-Coriander Rub: Pulse 1 tablespoon each fennel seeds and coriander seeds in a spice grinder until roughly ground. Transfer to a small bowl and mix in 1 teaspoon grated lemon zest and 1/2 teaspoon each garlic powder and red pepper flakes.