Ingredients

• 1 1/2 tablespoons minced garlic
• 1/3 cup extra-virgin olive oil, divided
• 6 plum tomatoes (2 pounds), halved lengthwise
• 1 large red onion, cut into 1-inch wedges (keep stem end intact)
• 3/4 pound spaghetti
• 1/3 cup grated parmesan
• 1/2 cup coarsely chopped basil
• Equipment: a 13-by 9- by 2-inch disposable foil pan
• Accompaniment: grated parmesan

Instructions

1. Prepare grill for direct-heat cooking over hot charcoal (high heat for gas), leaving about one third of grill free of coals (or, for a gas grill, shutting off one or two burners); see Grilling Procedure .
2. Put garlic and 1/4 cup oil in foil pan and put on grill over area with no coals.
3. Rub remaining oil all over tomatoes and onion and season with salt and pepper, then grill over coals, turning occasionally, until well browned, 4 to 5 minutes. Coarsely chop tomatoes and add to garlic oil with onion.
4. Cook spaghetti in a pasta pot of well-salted boiling water until al dente. Reserve 1/4 cup cooking water, then drain pasta. Toss with reserved water, parmesan, basil, contents of foil pan, and salt and pepper to taste.