Cut the tenderloin into ½" rounds and then cut each round into 3-4 strips.
In a large skillet or wok, heat 1 tablespoon of avocado oil over medium-high heat. Add the pork slices and stir-fry until no longer raw, about 5 minutes. Remove the pork to a plate and set aside.
Add the remaining oil to the skillet, then add the broccoli, peppers, red onions, and snap peas. Stir-fry the veggies until tender-crisp, about 3 minutes. Add the garlic and ginger and cook, stirring, for 30 seconds.
Reduce the heat to medium. Add the pork back to the skillet. Give the sauce a quick stir, then add it to the skillet. Continue to cook, stirring, until the sauce has thickened and the pork and vegetables are coated, about 2 more minutes.
Off heat, drizzle the dish with sesame oil and sprinkle it with sesame seeds. Serve immediately.
If the skillet becomes too dry at any point during cooking, add a splash of water.While you don't want the pork undercooked, you definitely don't want it overcooked. So during the first stage of cooking the meat and the onions, cook just until the meat is no longer raw. It will continue to cook during the next steps.The same goes for the veggies - you want them to retain their crispness and bright color, so take care not to overcook them.