Step 1

Combine shrimp, baking soda, salt, and sugar in a medium bowl and toss to coat. Thread shrimp onto sets of 2 skewers, alternating heads to tails and pushing shrimp so that they are nestled snugly together; you should have about 6 shrimp on each set of skewers. Lay skewers on top of a baking dish so that shrimp are suspended above bottom of dish. Transfer to refrigerator and allow to rest for 1 hour. Meanwhile, combine half of garlic and half of olive oil in a small bowl. Combine remaining garlic, olive oil, lemon zest and juice, and parsley leaves in a large bowl. Set aside.

Step 2

When shrimp are ready to grill, brush both sides with first garlic/oil mixture. Light 1 chimney full of charcoal. When all charcoal is lit and covered with gray ash, pour out and arrange coals on one side of charcoal grate. Set cooking grate in place, cover grill, and allow to preheat for 5 minutes. Alternatively, set half the burners on a gas grill to the highest heat setting, cover, and preheat for 10 minutes. Clean and oil grilling grate.

Step 3

Place shrimp directly over hot side of grill and cook, turning occasionally, until shrimp are just cooked through and well charred, 4 to 5 minutes total. Transfer shrimp to a cutting board.

Step 4

Carefully remove skewers from shrimp and transfer to bowl with garlic/oil/lemon mixture. Toss to coat. Season to taste with salt and pepper and serve immediately.