1. Preheat oven to 350°.
2. Place bread in a food processor; pulse 10 times or until coarse crumbs measure 3/4 cup. Arrange breadcrumbs on a baking sheet; bake at 350° for 8 minutes.
3. Heat a small skillet over medium-high heat. Coat pan with cooking spray. Add pancetta; sauté for 2 minutes. Add 1/2 cup shallots and carrot; sauté 8 minutes, stirring occasionally. Add tomato paste; cook 1 minute. Add wine; cook 2 minutes or until liquid almost evaporates, scraping pan to loosen browned bits. Remove pan from heat; cool 5 minutes. Combine the breadcrumbs, pancetta mixture, milk, and next 6 ingredients (through veal) in a large bowl; gently mix until just combined.
4. Transfer mixture to a 9 x 5-inch loaf pan coated with cooking spray; do not pack. Bake at 350° for 40 minutes or until a thermometer registers 160°. Let stand 10 minutes; cut into 6 slices.
5. To prepare sauce, melt butter in a medium saucepan over medium-high heat. Add cremini mushrooms and 2 tablespoons shallots; sauté for 6 minutes, stirring occasionally. Add flour, and cook for 1 minute. Add 1 cup beef broth; cook for 2 minutes, stirring frequently. Stir in half-and-half, 1/4 teaspoon black pepper, and dash of salt. Cook for 30 seconds. Serve with meat loaf.