5 tablespoons olive oil
1 large yellow onion, halved and thinly sliced
1 cup cherry tomatoes, halved
½ teaspoon salt, divided
¼ teaspoon black pepper, divided
6-ounces cream cheese, softened
3-ounces soft goat cheese
3 large garlic cloves, minced
16-ounces thin skirt steak, about ¼ inch thick
8 slices from French bread loaf, about ½ inch thick
4-6 fresh basil leaves, thinly sliced
3 tablespoons balsamic vinegar