Preheat the oven to 325°. Put the garlic in a small, deep baking dish and toss with the olive oil, lime juice and 1 teaspoon of salt. Cover and bake for about 30 minutes, until the garlic is soft and golden.
Increase the oven temperature to 400°. Combine all of the mushrooms in a 9-by-13-inch baking dish and toss with the roasted garlic and 1 teaspoon of salt. Cover with foil and bake for 10 minutes. Uncover and bake for about 35 minutes longer, until the mushrooms are tender and golden. Stir in the chopped cilantro.
Scrape some of the bread out of the center of the rolls and set the rolls on a large baking sheet, cut sides up. Spread the mushrooms over the rolls and bake for about 5 minutes to crisp the rolls. Spread the arugula and salsa on one half of the rolls and the goat cheese on the other half. Close the sandwiches and bake for about 5 minutes, until hot and crisp. Cut the sandwiches in half and serve.