Preheat the oven to 400°F.
Cut the spaghetti squash in half and remove the seeds. Massage the squash with a small dab of coconut oil and season with sea salt and pepper.
Place the squash cut-side down on a parchment-lined baking sheet and roast for 40-45 minutes, until the shell is easily pierced with a knife. Remove the squash and, once cool, shred with a fork.
Meanwhile, combine all the sauce ingredients in a small bowl and mix well.
Season the shrimp with salt and pepper. Heat a large wok or skillet over high heat and add a tablespoon of coconut oil. Add the shrimp and cook for 2-3 minutes until pink and no longer translucent. Transfer to a bowl and cover to keep warm.
Add two tablespoons of coconut oil to the wok. Add about half of the sliced eggplant. Stir-fry for 2-3 minutes, undisturbed, then stir and cook for another minute until just tender. Transfer to the bowl with the shrimp and repeat with the remaining eggplant.
Add the remaining tablespoon of coconut oil to the wok. Add the onions, pepper, and shiitakes and cook until the peppers are just tender, 4-5 minutes.
Push the vegetables to the side of the wok and add the garlic and ginger. Cook until fragrant, about 30 seconds.
Add the shrimp and eggplant back to the wok. Pour in the sauce and heat until thickened, about 4-5 minutes.
Stir in the basil and remove the wok from heat. Serve the stir-fry on top of the spaghetti squash and garnish with green onions, cashews and sesame seeds.