For the dressing, in a small mixing bowl stir together buttermilk, mayonnaise or salad dressing, basil, lemon juice, sugar, and pepper. Cover and chill in the refrigerator.
For salad, toss together the mixed greens, beef, parsnip, carrot, zucchini, and broccoli. Add the chilled dressing and toss to coat. Spoon onto 4 individual serving plates. Garnish with drained beets.