Peel and cube butternut squash; boil 8 minutes or until tender. Drain, puree and swirl squash using a blender or food processor until smooth. Swirl puréed squash into 2 large containers Boston Market Mashed Potatoes. Brown 4 tablespoons butter with 1/4 cup chopped sage and 1 teaspoon salt. Melt butter in a light-colored, heavy-bottomed skillet on medium heat. Stir continuously — the butter will foam and subside, and browned specks will begin to form. When the butter has a nutty aroma, remove from heat, and pour over mashed potatoes/squash mixture.