Pesto without garlic nuts

4 large red potatoes, cut into 1 inch pieces 1/2 teaspoon salt , for boiling potatoes water 3 tablespoons olive oil 1/4 teaspoon garlic powder 1/8 teaspoon[...]

2 tablespoons jarred pesto sauce 8 slices sourdough bread 4 slices fontina or 4 slices provolone cheese or 4 slices mozzarella cheese 1 (12 ounce) jar roasted[...]