Step by step

1. For the Yajin Kuli: In a small mixing bowl, combine groundnut/peanut butter powder, ground ginger, sweet paprika, onion powder, kosher salt, garlic powder, cayenne pepper powder, ground grains of selim (if desired), cubeb pepper, and ground cloves. Whisk to mix thoroughly, about 30 seconds. Set aside.
2. For the Suya: Wrap beef tightly in plastic wrap and place on a plate or small baking sheet and set in the freezer until the beef is partially frozen and firm to the touch, 15 to 30 minutes. Using a sharp chef's knife or slicing knife, slice beef against the grain into 2-inch-long, 1-inch-wide, and 1/8-inch-thick strips. (The easiest and most efficient way to do this is to start by portioning the beef into 2-inch-wide by 1-inch-thick pieces, and then slicing those pieces crosswise into 1/8-inch-thick strips.)
3. Place sliced beef in large mixing bowl and drizzle peanut oil over it. Sprinkle 1/2 cup of yajin kuli over the beef and carefully toss and massage spice rub into beef until it is evenly coated. Cover, place in refrigerator, and allow beef to marinate for at least 30 minutes and up to 8 hours.
4. Working with one piece of beef at a time, thread beef onto skewers, piercing each piece through twice to secure it, then bunching meat tightly together like an accordion. Continue threading beef onto skewer, making sure it's bunched tightly together, leaving no parts of the skewer exposed except for a 2-inch handle at the bottom and the pointy tip at the top. Repeat skewering process with remaining beef.
5. If Using Skewer-Specific Grill Setup: Set up grill for skewers, making sure to adjust distance between bricks to the length of your skewers. Light one chimney full of charcoal. When all the charcoal is lit and covered with gray ash, pour out and spread the coals evenly in the channel between bricks.
6. Place skewers directly over the hot coals, balancing them on top of the bricks, with the handles overhanging the bricks closest to you, and the tips balancing on the farther wall of bricks. Cook, turning frequently, until beef is lightly charred and a piece of beef looks cooked through when removed and cut in half, about 8 minutes. If flare-ups occur, move the skewers around as needed to get them away from the flames. Transfer to serving platter and let rest 2 to 3 minutes (see note).
7. If Using Conventional Charcoal or Gas Grill: Light 1 chimney full of charcoal. When all charcoal is lit and covered with gray ash, pour out and spread coals evenly over half of coal grate. Alternatively, set half the burners of a gas grill to high heat. Set cooking grate in place, cover grill, and allow to preheat for 5 minutes. Clean and oil grilling grate.
8. Place skewers on grate and cook over direct heat, turning once, until charred on both sides and a piece of beef looks cooked through when removed and cut in half, about 8 minutes. Transfer to serving platter and let rest 2 to 3 minutes (see note).
9. For Serving: Serve with reserved yajin kuli, thinly sliced red onions, tomatoes, lime halves, crisp lettuce, and coriander leaves and tender stems.