1.In a large skillet, heat canola oil over medium-high heat. Add shrimp and cook for about 2 to 3 minutes on each side (you may need to cook in two batches). Remove from the pan and set aside, covered.
2. In the same pan, add garlic and chili flakes and cook for 30 seconds.
3. Add butter, lemon juice, and cilantro. Stir, then add back in shrimp, turn off heat, and toss until covered. Season with salt and pepper.
4. Open brioche rolls and toast under the broiler, about 1 minute, until lightly golden.
5. Remove rolls from the oven. Layer with arugula first, then 5 shrimp on each roll. Spoon over extra melted butter from the pan. Repeat with all buns. Serve.