Nonstick cooking spray
5 tablespoons olive oil
6 tablespoons red-wine vinegar
2 garlic cloves, minced
1 teaspoon dried oregano
3/4 teaspoon salt
1/2 teaspoon black pepper
4 plum tomatoes, halved lengthwise
1 eggplant (1 1/2 pounds), cut into 1/2-inch slices
1 large red onion, cut into 1/2-inch slices
2 hot or sweet Italian sausages
8 ounces wagon-wheel pasta