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 have grill marks. You can algo grill the lemon halves. 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!