Stuffed Young Zucchini

Name: Stuffed Young Zucchini
Ingredients: 4 small zucchini, 5 to 6-inches long, 1 1/2-inches thick; 2 tablespoons extra-virgin olive oil; 12 crimini mushrooms, chopped; 1 small to medium yellow onion, chopped; 3 to 4 cloves garlic, grated or chopped; Salt and freshly ground black pepper; 2 vine ripe tomatoes or Roma tomatoes, seeded and chopped; 2 slices white toasting bread; Softened butter; A small handful flat-leaf parsley; A few sprigs fresh tarragon or a small handful basil leaves; 3/4 cup shredded Parmigiano-Reggiano; 1 egg, beaten