Preheat oven to 400. Arrange the baguette slices in a single layer on the baking sheet. Toast in oven for 3 to 5 minutes or until pale golden. Set aside.
In a large skillet, heat 3 tbsp of the oil over medium heat. Add the onions,cook for 15 to 20 minutes or until golden, stirring occasionally. Add the chopped garlic; cook for 30 seconds. Stir in the remaining 3 tbsp oil,the eggplant,zucchini,tomatoes,rosemary sprig,salt and pepper. Cook and stir for 5 minutes. Cover and reduce heat to low. Cook about 25 minutes more or until veggies are fork tender.
While the mixture cooks, chop the remaining garlic clove;set aside. Uncover the pan and increase the heat to medium-high. Cook about 10 minutes or until the mixture thickens. Remove the rosemary sprigs. Stir in the remaining garlic,the basil,lemon juice and chopped rosemary.
Preheat broiler. Transfer the vegetable mixture to a 2 to 3 quart casserole dish. Arrange the toasted baguette slices over top. Brush the bread with additional olive oil. Top evenly with pepper Jack cheese. Broil 4 to 5 inches fro heat for 1 to 2 minutes or until the bread is golden and cheese has melted.