Preheat oven to 400 degrees F. In a small bowl combine halved grapes, cheese, and walnuts. Set aside.
For pastry packages, unfold phyllo dough. Cover phyllo with plastic wrap to help keep it from drying out; remove sheets as needed. Brush 1 phyllo sheet with some of the melted margarine or butter. Top with another sheet of phyllo and brush with some of the melted margarine. Add 1 more sheet for a total of 3 sheets, brushing each sheet with margarine. Use remaining phyllo and melted margarine to make a second 3-layer stack of phyllo. Trim each stack into a 14-inch square; cut each large square into four 7-inch squares.
Place 1/4 cup of the grape-cheese mixture onto the center of one 7-inch square. Fold 2 opposite sides of phyllo over filling; fold remaining 2 sides of phyllo over, forming a square package. Press edges lightly to seal. Place, seam side down, on a lightly greased or parchment-lined baking sheet or 15x10x1-inch baking pan. Repeat with remaining phyllo squares and filling. Brush with any remaining melted margarine. Bake 10 minutes or until golden.
For dressing, in a food processor bowl or blender container combine vinegar, garlic, and thyme. With food processor or blender running, slowly add the 1/4 cup salad oil; process or blend until combined. Add salt to taste.
To serve, for each salad, place one pastry package in the center of a salad plate. Surround with spinach or salad greens and red-tip lettuce or radicchio. Drizzle the greens with 1 tablespoon of the dressing. Sprinkle with pepper. If desired, garnish with small clusters of grapes and fresh chives. Makes 8 side-dish salads.