Infuse the Oil: Place a large skillet or Dutch oven over medium heat and add the olive oil. When it shimmers, add the garlic and red pepper flakes. Sauté about 45 seconds until fragrant and pale golden. Do not brown.
Sear the Shrimp: Increase heat to medium-high. Add half the shrimp in a single layer and sear 60 to 90 seconds per side until just turning pink. Transfer to a plate and repeat with remaining shrimp. The shrimp are not fully cooked yet.
Deglaze: Return the pot to medium-high. Pour in the wine or broth, scraping up any browned bits.
Steam the Vegetables: Add broccoli and bell pepper. Season with half the salt and half the black pepper. Stir, cover, reduce heat to medium, and cook 4 to 6 minutes until the broccoli is crisp-tender.
Final Toss: Uncover. Return shrimp and any accumulated juices, add lemon juice and the remaining salt and pepper. Toss 1 to 2 minutes until the shrimp are opaque, curled, and just cooked through. Target internal temperature 63°C.
Garnish and Serve: Remove from heat. Stir in parsley. Serve on its own or over zucchini noodles or cauliflower rice.