Rinse all vegetables. Peel and slice carrots into 1/4-inch coins or diagonal slices (about 2 cups). Cut broccoli and cauliflower into bite-sized florets (2 cups broccoli, 1 cup cauliflower). Trim ends from sugar snap peas or snow peas. Seed and thinly slice the red bell pepper into 1/2-inch strips (about 1 cup). Thinly slice the yellow onion to measure 1/2 cup.

Measure aromatics and sauce

Mince 2 cloves garlic and grate about 1 teaspoon fresh ginger. In a small bowl whisk together 2 tablespoons soy sauce, 1 teaspoon sesame oil, 3 tablespoons water or vegetable broth and 1 teaspoon cornstarch until fully combined and no lumps remain. Have salt, pepper and optional red pepper flakes ready.

Cooking

Heat the pan

Place a large skillet or wok over medium-high heat. Add 2 tablespoons vegetable oil and heat until shimmering but not smoking (about 30–60 seconds).

Start with aromatics

Add sliced onion to the hot oil and stir-fry for 1 minute until it begins to soften. Add the minced garlic and grated ginger and stir constantly for 20–30 seconds until fragrant. Be careful not to burn the garlic.

Cook firmer vegetables

Add the carrots, broccoli and cauliflower to the pan. Stir-fry for 3–4 minutes, tossing frequently so they cook evenly and begin to turn bright in color but remain slightly firm.

Add remaining vegetables

Add the red bell pepper and sugar snap peas. Continue stir-frying for another 2–3 minutes until peppers are tender-crisp and peas are heated through. Total vegetable cooking time should be about 5–7 minutes depending on desired tenderness.

Add sauce and season

Stir the soy-sesame-cornstarch mixture again (to reincorporate cornstarch) and pour it into the pan. Add 1/2 teaspoon salt, 1/4 teaspoon freshly ground black pepper and optional 1/4 teaspoon red pepper flakes. Toss continuously for 1–2 minutes as the sauce thickens and glazes the vegetables. If the sauce thickens too much, add 1 tablespoon water at a time to reach desired consistency.

Finish

Remove the pan from heat once vegetables are coated and at your preferred doneness. Taste and adjust seasoning with a pinch more salt or a splash of soy sauce if needed. Drizzle a touch more sesame oil if desired (about 1/4 teaspoon) for aroma.

Serve & Garnish

Transfer the mixed vegetables to a serving dish. Sprinkle with 1 teaspoon sesame seeds and 2 tablespoons sliced green onions or cilantro if using. Serve immediately with lemon or lime wedges on the side for a bright finish.

Suggested accompaniments: steamed rice, quinoa, noodles, or as a side to grilled protein.