Pre-heat oven to 450 degrees and line a baking sheet with foil.
Scatter the shrimp in a single layer on the baking sheet and drizzle with olive oil, garlic, lemon zest, salt and chili flakes. Toss well to make sure shrimp is evenly coated. Roast until bright pink and cooked through, about 6-7 minutes, being careful not to overcook.