Chop the onion and ginger.

Blend the onion, ginger, and peanut oil until smooth.

Add salt and pepper to the blended mixture.

Pour the mixture into a resealable bag and add the lamb cubes.

Seal the bag and coat the meat thoroughly.

Chill the marinated lamb for at least 4 hours, or overnight.

Whisk together powdered peanut butter, paprika, ground ginger, pepper, salt, and cinnamon in a bowl to make the dry rub.

Set aside a small amount of the dry rub for spiced yogurt sauce (if making).

Let the meat come to room temperature about 1 hour before cooking.

Soak bamboo skewers in water for at least 30 minutes.

Thread about 6 chunks of marinated meat onto each skewer.

Prepare a charcoal grill with mesquite lump charcoal and mesquite charcoal briquets, or heat a gas grill to medium (400°F).

Oil the cooking grate.

Grill the skewers, covered and turning once, until medium-rare, about 6-8 minutes total.

Transfer the skewers to a baking sheet.

Sprinkle the skewers heavily on all sides with the dry rub.

Let the meat rest for 2-3 minutes.

Set the skewers on a platter.

Drizzle with yogurt sauce (if making).

Scatter with smoked paprika and fresh herb sprigs.

Serve more sauce on the side.