These tacos are deliberately mild so they will appeal to a wide variety of palates. If your kids like the taste of packaged taco seasoning or taco sauce, you can simply add it to this recipe.
Heat oil in a deep skillet over medium heat. Cook the onions until they are slightly translucent and then add the beef (or turkey), stirring to break it up, cooking about 5 minutes until meat is no longer red. Add the salt, a few grinds of pepper, Purple Purée, salsa, and tomato paste and mix well until heated through and the colors blend into a brown mixture, stirring occasionally, about 5 minutes.
Spoon about ¼ cup filling into each taco shell. Add toppings as desired.