Bring a pot of salted water to a boil, then add the broccoli florets and blanch for 30 seconds to 1 minute until bright green and slightly tender. Use a slotted spoon to transfer the broccoli into ice water to stop the cooking process and keep it crisp.
While the broccoli cools, pat the shrimp dry with paper towels. Mince the garlic finely and prepare the soy sauce and lemon juice mixture in a small bowl.
Heat the wok over high heat until shimmering, then add 1-2 tablespoons of vegetable oil. Once hot, add the minced garlic and cook for about 15 seconds until fragrant and slightly golden, but not burnt.
Add the shrimp in a single layer to the hot pan. Cook for about 2 minutes, then flip and cook for another 1-2 minutes until they turn opaque and pink. Remove the shrimp from the pan and set aside.
Add the drained broccoli to the same hot pan. Toss quickly for about 30 seconds, allowing the broccoli to heat through while maintaining its crispness and vibrant color.
Return the cooked shrimp to the wok. Pour the soy sauce and lemon juice mixture over everything, tossing gently to coat evenly. Stir-fry for another 30 seconds until everything is glossy and heated through.
Squeeze fresh lemon juice over the stir-fry for a bright finish. Give everything one last toss and remove from heat. Serve immediately while hot, garnished with optional sesame seeds or red pepper flakes if desired.
