Step 1Combine the shrimp and one-third cup charmoula in a large nonreactive bowl or resealable plastic bag and marinate in the refrigerator for 2 hours. Ten minutes before removing the shrimp from the refrigerator, soak the bamboo skewers in water to prevent the wood from burning.
Step 2Remove the shrimp from the marinade and thread with the lemon slices onto the prepared bamboo skewers.
Step 3Heat the grill over medium-high heat. When the grill is hot, oil the rack and place the skewers on top. Grill the skewers until the shrimp are puffy, pink and opaque, about 2 to 3 minutes per side. Serve immediately with the remaining charmoula sauce.