1. Preheat oven to 375 degrees F. Coat an 8 1/2-by-4 1/2-inch loaf pan with cooking spray.
2. Heat oil in a large nonstick skillet over medium-high heat. Add onion and cook, stirring often, until translucent and starting to brown, about 5 minutes. Pour in beer and increase heat to high. Bring to a vigorous boil; cook until the liquid is quite syrupy and the mixture reduces to about 3/4 cup, 8 to 10 minutes. Transfer to a large bowl. Stir in thyme, dry mustard, salt and pepper. Let cool for 10 minutes.
3. Add beef, turkey, breadcrumbs, parsley, beaten egg and egg white to the onion mixture. Mix thoroughly with clean hands and transfer to the prepared pan.
4. Bake the meatloaf until an instant-read thermometer registers 160 degrees F when inserted into the center, about 1 hour 20 minutes. Let rest for 5 minutes; drain accumulated liquid from the pan and slice. Serve hot or cold or in a sandwich.

Yield: 8 servings