Begin by trimming the woody ends off the asparagus and cutting the spears into 2-inch pieces. Set aside.
Heat your wok or deep skillet over medium-high heat until it shimmers, then add a tablespoon of sesame oil. Swirl to coat the pan evenly.
Add the minced garlic to the hot oil, listening for a gentle crackle and aroma of toasted garlic, cooking for about 30 seconds until fragrant.
Toss in the prepared asparagus pieces, spreading them out in a single layer. Let them sear undisturbed for 1-2 minutes until edges start to caramelize and they turn a vibrant green.
Stir the asparagus continuously for another 2-3 minutes, ensuring they stay crisp-tender and develop some slight char on the tips.
Mix the soy sauce and rice vinegar in a small bowl, then pour this mixture over the asparagus. Cook for another minute, stirring until the sauce thickens slightly and coats the spears evenly.
Sprinkle red pepper flakes and sesame seeds over the dish, giving everything a quick toss to distribute the flavors evenly.
Turn off the heat and squeeze fresh lemon juice over the stir fry for a bright, citrusy finish. Give it a final toss.
Serve immediately on a warm plate, garnished with extra sesame seeds if desired, and enjoy the vibrant crunch and savory aroma.