Grilled Veggie Kabobs With Green Goddess Dressing

Name: Grilled Veggie Kabobs With Green Goddess Dressing
Ingredients: 1 small garlic clove; 2 Tablespoons fresh tarragon; 4 Tablespoons fresh chives; 2 Tablespoons extra-virgin olive oil; 2 Tablespoons lemon juice; 1 Tablespoon apple cider vinegar; 4 Tablespoons mayonnaise; 2 Tablespoons water; 1/3 Cup avocado; 1/4 Teaspoon salt; Freshly ground black pepper, to taste; 2 red bell peppers; 2 red onions; 1 large zucchini; 4 button mushrooms; Extra-virgin olive oil; Kosher salt; Freshly ground black pepper