Make the marinade: In a bowl, mix the olive oil, lemon zest, freshly squeezed lemon juice, minced garlic, chopped Italian parsley, red pepper chili flakes, honey, salt and pepper until well-combined. Transfer the marinade into a large resealable bag.
Prep the shrimp: Using kitchen shears, remove the shell but leave the lower part of the tail attached to the shrimp. Pat dry.
Marinate: Add the shrimp into the marinade in the bag, make sure everything is well coated. Seal the bag and refrigerate for 30 minutes (max 45 mins). Tip: Because this is a citrus marinade, leaving it for too long can cause the shrimp to turn rubbery.
Preheat grill: Meanwhile, preheat your grill to medium-high heat. Preheating properly prevents food from sticking to the grates.
Thread in skewers: Assemble the marinated shrimp into metal skewers. I used one pound of shrimp, and it yielded 4 skewers with 6-7 shrimp in each. Note: If using bamboo skewers, soak them in water first to prevent them from burning.
Grill: Grill the shrimp skewers for about 4 minutes per side, until cooked through and grill marks form. You can algo grill the lemon halves. Note: Shrimp cooks really fast, don't overcook. It's ready when it turns orange and white in color and turns into a "C" shape.
Serve with a good squeeze of the grilled lemon halves and parsley, and crumbled feta cheese. Enjoy!