In a small bowl, whisk together the low-sodium soy sauce, oyster sauce, toasted sesame oil, and cornstarch slurry until well combined. Set aside.

Heat 15 ml of avocado oil in a large skillet or wok over medium-high heat. Add sliced mushrooms and sear without stirring for 2-3 minutes until browned on the bottom, then stir and cook for another 2 minutes. Remove mushrooms from the pan and set aside.

Add the remaining 15 ml of oil to the same pan. Stir in the trimmed asparagus pieces and cook for 3 to 4 minutes, stirring frequently, until bright green and tender-crisp.

Reduce heat to medium. Add minced garlic, grated ginger, and red pepper flakes (if using) to the pan with the asparagus, stirring constantly for 30 seconds until fragrant.

Return the browned mushrooms to the pan. Give the sauce mixture a quick stir and pour it over the vegetables. Toss everything together for 1 to 2 minutes until the sauce thickens and evenly coats the asparagus and mushroom mix.

Remove from heat, transfer to a platter, and sprinkle with toasted sesame seeds before serving hot.