I'd guess that most people who've swore off eating grains (or at least wheat) have wondered if there's a product that can substitute better for spaghetti than the usual spaghetti squash. As it turns out, Asian glass noodles (as used in Korean japchae) do a good job of this. Check the ingredients before making any purchases, of course, but most of the ones I've seen are 100% condensed vegetable starch (typically potato, sweet potato, or tapioca/cassava).
A word of warning that glass noodles do tend to be more sticky/clumpy than wheat-based noodles, though. I don't really mind since I'm fine with attacking the dish to break it up, but if you dislike this, you'll want to do some multitasking during cooking to reduce the resting time between draining the noodles and adding them back into the stir fry, and you'll also want to reheat any leftovers to melt any hardened coconut oil (a simple 15-30 seconds in a microwave should be all that's needed for this purpose).
125-175 grams glass noodles (I eyeball about a quarter of a resealable 600 gram package)
350-400 grams extra firm tofu, cut into bite-sized pieces (soy-free alternative: 14 oz. can of chopped jackfruit)
half of a napa cabbage, chopped roughly
1 large bell pepper or 1 large banana pepper, chopped
1 Tbsp coconut oil
2 cups water
2 Tbsp avocado oil (or a separate 2 Tbsp coconut oil)
3 Tbsp tamari sauce (soy-free alternative: 3 Tbsp coconut aminos)
1 tsp sesame seeds
Put water and coconut oil into a wok or deep pan and bring to a light boil.
Add glass noodles. Let boil for 10 minutes.
Drain in a colander. Set aside.
Place avocado oil into the wok/pan over medium heat. Allow it to heat up enough to make a drop of water sizzle immediately.
Add tofu (or jackfruit), chopped pepper, 2 Tbsp tamari sauce (or coconut aminos), and seasoning.
Cook until pepper pieces soften, stirring frequently.
Reduce to medium-low heat.
Add chopped napa cabbage, remaining tamari sauce (or coconut aminos), and sesame seeds. Cook covered for 2 minutes, stirring frequently.
Add noodles. Stir thoroughly, then turn off heat and let the mixture sit covered for 2 minutes.