Preheat oven to 420 degrees. Cut out the flesh of both halves of the eggplant, and dice. Transfer eggplant flesh to a colander, and sprinkle with salt.
Brush eggplant skins with avocado oil, and place on baking sheet. Place in the oven and bake for 15-20 minutes until soft.
While the eggplant bakes, heat the coconut oil in a medium sized sauce pan on medium heat. Add in the onion and the diced eggplant flesh, and cook, mixing often, for 2-3 minutes.
Add in the quinoa and let it toast on the bottom of the pan, again stirring regularly, for a minute. Add in 2 cups of water and bring to a boil. Once boiling, cover and simmer until the liquid evaporates.
Once the quinoa has cooked, remove from heat and add in the chopped spinach. Cover immediately and let the spinach leaves wilt for 2-3 minutes.
Once the spinach has wilted, mix in the lemon juice and tahini. Season with salt and pepper.
Spoon the quinoa mixture into the cooked eggplant skins. Place back in the oven for 10 minutes to get a crispy topping on the quinoa, and serve immediately.