Prep the shrimp: Pat the shrimp dry with paper towels. Season with a pinch of salt and black pepper.
Dry shrimp sear better and stay juicy.
Blanch or quick-steam the broccoli (optional): For crisp-tender broccoli, microwave with a splash of water for 1–2 minutes, or blanch in boiling water for 1 minute, then drain. This speeds up the stir-fry and prevents burnt garlic later.
Mix the sauce: In a small bowl, combine broth, lemon juice, soy sauce, and red pepper flakes. If you want a slightly thicker sauce, stir cornstarch with 2 tablespoons of water in a separate bowl to make a slurry.
Set both aside.
Sear the shrimp: Heat 1 tablespoon olive oil in a large skillet over medium-high heat. Add the shrimp in a single layer. Cook 1–2 minutes per side until pink and just opaque.
Remove to a plate. Do not overcook.
Sauté the garlic: If the pan looks dry, add 1 teaspoon oil. Reduce heat to medium.
Add minced garlic and cook 20–30 seconds until fragrant, stirring constantly so it doesn’t brown.
Cook the broccoli: Add broccoli to the pan with the garlic. Toss for 2–3 minutes until bright green and tender-crisp. Sprinkle with a pinch of salt and pepper.
Add the sauce: Pour in the broth-lemon-soy mixture.
Let it bubble for 30–60 seconds. If using the cornstarch slurry, stir it in now and cook until the sauce lightly thickens and coats the broccoli.
Return the shrimp: Add the shrimp back to the pan along with lemon zest. Toss to coat for 30–60 seconds, just to warm through.
Taste and adjust salt, pepper, and lemon.
Garnish and serve: Remove from heat and sprinkle with parsley or green onions. Serve as is, or over cauliflower rice, brown rice, or zucchini noodles.