First take your shrimp in a large bowl or ziplock bag and add your blueberry juice. Shake or stir and place in fridge for 8-24 hours. The longer it marinates the sweeter it will be.
Once shrimp is done marinating, remove from marinade and pat off with a paper towel. In a bowl add your shrimp, lemon juice, garlic powder, garam masala, cayenne pepper, salt & 1 tbsp olive oil. Mix together until shrimp is evenly coated.
On a grill pan (or out on a grill over medium high heat) Add a little bit of oil to prevent sticking and then add your shrimp (without over crowding pan or grill) Cook about 2 minutes on each side (total 3-4 minutes if they are medium sized shrimp, 2-3 minutes if they are small, 4-5 minutes if they are larger shrimp) and remove from heat. Serve warm or at room temperature. Optional cocktail sauce for dipping.
Recipe by My Lavender Blues at https://mylavenderblues.com/spiced-blueberry-shrimp/