Spaghetti Squash. Preheat oven to 400 F. Slice spaghetti squash in half and place cut side down on a rimmed baking sheet. Bake in preheated oven for 30-40 minutes -- you'll know your squash is done once the squash is fork-tender. Allow the squash to cool, then use a spoon to remove the seeds. Run a fork through the flesh of the spaghetti squash to form "noodles". Measure 5 cups of spaghetti squash, and discard or save the rest for another recipe. Place spaghetti squash noodles on a paper towel-lined plate, and place paper towels on top. Set aside while we prep the rest.
Sauce. Whisk ingredients for the sauce in a medium bowl and set aside.
Chicken. Heat oil in a large pan over medium-high heat. Once shimmering, add the chicken. Give it a stir so the pieces don't stick together. Cook chicken until no longer pink -- about 4-5 minutes on each side. If you have one, a fryer screen is suuuper helpful here! Place cooked chicken on a plate and set aside.
Aromatics + eggs. If there's no oil left in the pan, add an additional tablespoon, and reduce the heat to medium. Add garlic, scallions, and red onion, and saute until the garlic is fragrant (about 2-3 minutes). Add eggs and scramble, breaking them into small pieces as they cook.
Assemble. Add sauce, chicken, and spaghetti squash back to the pan, and stir to coat. Continue to cook until the dish is heated through. Scoop up a serving, cover with toppings, and twirl/slurp away!