This is a good dip for most roasted vegetables. Summer squash, of course, can be used with or instead of zucchini.

3/4 c mayonnaise
1/3 c buttermilk or yogurt
1/2 c coarsely chopped basil leaves
1/4 c coarsely chopped scallions
1 T white wine vinegar
salt and pepper, to taste

Roasted Zucchini:
2 or 3 zucchini and/or summer squash
1 T  olive oil
salt and pepper, to taste

1. For dip: Combine mayo, buttermilk or yogurt, basil, scallions, vinegar, salt, and pepper in a blender. Whizz until smooth. Transfer to a small bowl and chill in refrigerator.

2. For roasted vegetables: Preheat oven to 400ºF. Cut the zucchini and/or summer squash into sticks (think picking them up with your hand and dipping them to get an idea of the size). Toss with oil, salt, and pepper. Transfer to a cookie sheet and roast until tender, about 15 minutes. Let cool some, then serve slightly warm or at room temperature.