Turn the wok to the highest setting. Let it heat for about 5 minutes while you prep the veggies.
Once the wok is very hot. Drizzle the sesame oil in the skillet. Add the broccoli. Stir-fry for 2-3 minutes until bright green and slightly softened. Season with salt and pepper.
Add the bell pepper, onion, and mushrooms. Stir-fry another 3-4 minutes until everything starts to slightly soften. Season again with a little pinch of salt and pepper.
Add the carrots, baby corn, snow peas, asparagus, and garlic. Continue to stir-fry until the asparagus is bright green, slightly softened, but still crisp, another 2-3 minutes. Season one more time with a little bit of salt and pepper.
While the veggies finish, add soy sauce, mirin, and sambal oelek (also corn starch if using) to a small bowl. Whisk to combine. If you want a thicker sauce that coats the veggies really well, add the cornstarch. If you like a looser sauce that drips down to the rice, leave it out.
Pour the sauce over the veggies, stir-fry another 2-3 minutes until the sauce coats the veggies. Season to taste with salt, pepper, and more sambal oelek if desired. Serve over rice.