How to Make It
Preheat the oven to 375°. Line a rimmed baking sheet with parchment paper. In a food processor, pulse the mushrooms until finely chopped and scrape into a large bowl. Add the cereal and chicken broth to the processor and pulse until the cereal is coarsely crushed. Add to the mushrooms along with the egg whites, garlic, 1/4 cup of the ketchup and the salt and pepper. Add the beef and turkey and mix well with your hands.
On the prepared baking sheet, shape the meat mixture into a 12-by-5-inch oval and spread the remaining 1/4 cup of ketchup on top. Bake for 30 minutes, until an instant-read thermometer inserted in the center of the loaf registers 165°. Let stand for 5 minutes before slicing.
Mashed potatoes and roasted tomatoes.