Can be prepared in 45 minutes or less but requires additional unattended time.
Ingredients
Preparation
Step 1
In a large saucepan of boiling salted water cook carrots 1 minute. Add yellow squash and zucchini and cook vegetables 5 minutes. Transfer vegetables with a slotted spoon to a large bowl of ice and cold water to stop cooking and drain well in a colander. Transfer vegetables to a bowl. (If using larger yellow squash and zucchini cut them into a total of thirty-two 3/4-inch pieces.) In boiling water remaining in pan cook onions 4 minutes and transfer with slotted spoon to bowl of ice and cold water. Drain onions well in colander and peel, leaving root ends intact. Vegetables may be boiled 1 day ahead and chilled in sealable plastic bags.
Step 2
In a small bowl whisk together vinegar, mustard, oil, and salt and pepper to taste. Basting sauce may be made 1 day ahead and chilled, covered.
Step 3
Prepare grill.
Step 4
Thread vegetables, alternating them, onto skewers. Brush one side of kebabs with about half of sauce and grill, coated side down, on an oiled rack set 5 to 6 inches over glowing coals 5 minutes. Brush kebabs with remaining sauce and turn. Grill kebabs 5 minutes more, or until squash is tender. (Alternatively, kebabs may be grilled in a hot well-seasoned ridged grill pan over moderately high heat.)
