Cook tortellini according to package directions. Drain and toss with 1/2 teaspoon olive oil. Set aside.
Place spinach, kale, salt, garlic, walnuts, and parmesan cheese in a blender or food processor.
With motor running, slowly drizzle in olive oil until you reach the desired consistency (you may not use all of the olive oil).
Toss cooked tortellini with a heaping spoonful or two of the pesto (as much as you like).
Serve warm or cold, with additional parmesan cheese.
Pack up leftover pesto tortellini in airtight containers for lunch boxes. (Be sure to use a cold pack in lunch boxes.)
Store leftover pesto in an airtight container and refrigerate if using within the next week. Otherwise, place in freezer.