Heat a tablespoon of olive oil in a skillet over medium heat. Add sliced scallions and garlic and sauté until softened, about 5 minutes.
Stir in spaghetti squash and cook 2 minutes. Add taco seasoning and 2/3 cup of water and stir to combine. Let simmer until most of the liquid has disappeared, about 5-7 minutes.
Serve with warm flour tortillas, sliced scallions, cilantro, tomatoes, and jalapenos.