Add another tablespoon of oil to the wok/skillet. Once, shimmering, add the onions, sauté over medium-high heat for ~3 minutes or until fragrant.
Add the garlic and veggies (except the spinach) continue to cook for 3-5 minutes until tender but still crisp. Keep the veggies moving to prevent sticking (add a splash of water or broth if necessary).
Next add the soy curls back in along with the spinach, half the cashews, and ¾ of the sauce. Stir to combine. Allow the sauce to simmer over medium heat for 1 to 2 minutes to thicken.
Add the remaining sauce if the stir-fry is dry or you like a super saucy stir fry (this will vary depending on the amount and type of vegetables you choose as well). If the sauce gets too thick, add a splash or two of water/broth to correct.
Remove from heat, garnish with remaining cashews, green onions, and sesame seeds. Dig in!