Portobello-Mushroom and Red-Pepper Pizza

2 red bell pepper s, cut into thin slices

1 1/2 pounds portobello mushroom s, stems removed, caps cut into 1/4-inch slices

1 teaspoon salt

1 pound store-bought or homemade pizza dough

3 cloves garlic , minced

1/4 teaspoon fresh-ground black pepper

3/4 cup lightly packed basil leaves, chopped

1/2 pound fresh salted mozzarella , cut into 1/4-inch cubes

1/2 cup grated Parmesan