Grilled Zucchini with Buttermilk and Basil Dressing

5 tbsp buttermilk
6 tbsp olive oil
1 garlic clove, minced
1 cup packed fresh basil leaves
1/3 cup coarsely grated parmesan
salt and pepper
4 medium zucchini or yellow squash, halved and cut lengthwise into 1/4 inch slices

1. 1. Heat a grill or grill pan over high. Clean and lightly oil hot grill. In a small measuring cup, combine buttermilk and 5 tablespoons extra-virgin olive oil with white-wine vinegar. In a food processor, combine garlic, basil, and Parmesan and process until basil is finely chopped. Season with salt and pepper. With machine running, add buttermilk mixture in a slow, steady stream and process until dressing is smooth. Season to taste with salt and pepper.
2. 2. Toss zucchini with remaining tablespoon oil; season with salt and pepper. Grill zucchini (in batches if necessary) until lightly charred and tender, 4 to 6 minutes, flipping once. Transfer to a serving plate and drizzle with dressing.