To prepare a Megans spaghetti squash tacos recipe, you'll first need to prepare the squash. First, cut it in half and scoop out the seeds. Then, slice it lengthwise, and then cut the flesh into bite-sized pieces. Place the pieces of squash in the bottom of an oven-proof skillet. Heat the oil over medium-high heat. Add the onion and garlic and cook until the onions are translucent, about 5 minutes. Remove the skillet from the heat and add the tomato paste. Stir to coat the ingredients. Cook the mixture for 2 minutes, then stir in 2 tablespoons of the sour cream. Pour the sauce over the vegetables and stir to combine. Serve with tortilla chips.