How to Make Sage-Walnut Butter
- Combine balsamic vinegar, honey and a bay leaf in a saucepan over medium-high heat; cook until syrupy, 5 minutes.
- Melt the butter in a large skillet over medium heat, then add the sage leaves and chopped walnuts; cook 3 minutes. Add the pasta-cooking water and cook until reduced by half, 2 minutes.
- Toss with the cooked tortellini, some grated parmesan cheese and salt. Drizzle with the balsamic syrup.