Preheat and Prep Broccoli: Position an oven rack in the center and preheat your oven to 390∘F (199∘C). On a large, rimmed baking sheet, combine the broccoli florets with the avocado oil, garlic powder, a pinch of salt, and a few grinds of black pepper. Toss thoroughly to ensure the broccoli is evenly coated. Arrange the broccoli in a single layer for even roasting.
Initial Broccoli Roast: Transfer the baking sheet to the preheated oven. Roast the broccoli for 11−12 minutes, or until it begins to soften and show slight charring at the edges.
Whisk Together Marinade: While the broccoli is in its initial roast, prepare the spicy garlic marinade. In a small mixing bowl, whisk together the low-sodium tamari (or soy sauce), freshly grated ginger, chili-garlic sauce, and toasted sesame oil until well combined. Set this aside.
Add Shrimp and Sauce: Pat the peeled and deveined shrimp dry with paper towels and season them lightly with a touch more salt and pepper. Once the broccoli's initial roasting time is up, carefully remove the baking sheet from the oven. Distribute the seasoned shrimp amongst the broccoli on the sheet. Pour the prepared spicy garlic marinade evenly over both the shrimp and the broccoli. Gently toss everything together directly on the baking sheet to ensure all pieces are well-coated. Spread the mixture back into a single layer.
Final Roast: Return the baking sheet to the oven. Continue to roast for an additional 7−9 minutes. Stir the contents gently about halfway through this final roasting period. The dish is ready when the shrimp are pink, opaque, and fully cooked through, and the broccoli is tender-crisp and slightly caramelized. Take care not to overcook the shrimp, as they can become tough.
Serve and Garnish: Remove the sheet pan from the oven. Serve the Zesty Roasted Chili-Garlic Shrimp and Broccoli immediately. It's delicious served over a bed of quinoa, brown rice, or cauliflower rice (if using). Garnish with a sprinkle of freshly sliced green onions and offer lime wedges on the side for a bright, citrusy finish, if desired. Enjoy your flavorful and healthy meal!