1. Prepare beef: Slice beef into thin, even strips or small cubes, about 1/4-inch thick. Pat the beef dry thoroughly with paper towels to ensure better spice adhesion.

2. Make Suya spice (Yaji): In a medium bowl, combine the finely ground roasted peanuts, paprika, cayenne pepper, garlic powder, onion powder, ground ginger, salt, and black pepper. Mix thoroughly until all spices are evenly distributed.

3. Marinate beef: In a large bowl, add the prepared beef. Toss the beef with 3-4 tablespoons of the Suya spice mix and 2 tablespoons of vegetable oil. Use your hands to ensure every piece of beef is well coated with the spice mixture.

4. Chill: Cover the bowl with plastic wrap and refrigerate for at least 2 hours, or preferably overnight, to allow the flavors to deeply meld into the meat.

5. Preheat grill: If using wooden skewers, soak them in water for at least 30 minutes to prevent burning. Preheat your grill (charcoal or gas) to medium-high heat. The grill should be hot enough to get a good char.

6. Skewer the beef: Thread the marinated beef strips onto the soaked skewers, making sure not to pack them too tightly so they cook evenly.

7. Grill Suya: Lightly brush the grill grates with a little vegetable oil to prevent sticking. Place the skewers on the hot grill. Grill for 3-4 minutes per side, turning occasionally, until the beef is cooked to your desired doneness and has nice charred edges.

8. Serve: Remove the cooked Suya from the grill. Serve immediately, garnished with fresh slices of red onion, tomato, lime wedges, and a generous sprinkle of additional Suya spice mix. Enjoy hot!