Season shrimp with salt and pepper then sauté in 1 tbsp of vegetable oil over medium-high heat in a large wok for 3 to 5 minutes, or until no longer translucent. Remove to a plate and keep warm.: The moment the oil hits the hot wok you will hear a pronounced sizzle, and that sound is your cue that the pan is ready to give the shrimp a golden sear. As the shrimp cooks, it will change from translucent to opaque and firm up, and you may notice the scent become briny and slightly sweet. Searing quickly at medium high heat creates a caramelized surface that adds depth, while removing them to a plate prevents overcooking, which is the most common pitfall here. If the shrimp start releasing large amounts of liquid, the pan is not hot enough, and you will steam instead of sear.
Snap off and discard woody bases from asparagus. If desired, scrape off scales. Cut asparagus diagonally into 2-inch pieces (you should have about 3 cups).: When you break the asparagus, the woody end naturally snaps where the tender part begins, and that tactile break is a quick test of freshness. Cutting on the diagonal increases the searing surface and gives attractive pieces that show off the vegetable's bright green color. The visual cue you want is vivid green with no limp spots, and the aroma should be fresh and grassy. A common mistake is leaving the tough base on, which results in chewy bites, so do not skip snapping or trimming.
Pour remaining vegetable oil into the wok; heat wok over medium-high heat. Add ginger and garlic; cook and stir for 15 seconds. Add asparagus, sweet pepper, and red onion; cook and stir for 3 minutes. Add sugar snap peas and sesame seeds; cook and stir for 3 to 4 minutes more or until vegetables are crisp-tender.: As the oil warms and the ginger hits the pan you will smell fragrant, peppery steam, and that quick flash cooks out rawness while preserving brightness. When you add the cut vegetables, listen for the lively sizzle and watch for the edges to take on slight browning while the interiors remain firm. The sweet pepper and red onion will begin to soften and release sugars that enhance the sauce later. After adding the sugar snap peas , the pan should still be noisy with quick pops and cracks, which is perfect. Overcrowding is a typical error, it causes steaming instead of searing, so keep the pan roomy and stir frequently.
Add soy sauce, vinegar, brown sugar, and sesame oil to vegetable mixture; return shrimp to wok and toss gently to coat. Stir in cilantro. Use a slotted spoon for serving.: The moment the sauce hits the hot vegetables the aromas will lift, a balance of savory soy sauce , bright rice vinegar , and caramel brown sugar . Tossing the reserved shrimp back in warms them through and lets the glaze cling to every surface, creating glossy bites. The final stir with chopped cilantro releases herbal perfume and adds a fresh counterpoint. Avoid vigorous tossing that breaks the vegetables; gentle movement ensures an even coating without mashing delicate pieces, which is a frequent misstep at this stage.