Preheat oven to 375 degrees F. Coat a large rimmed baking sheet with cooking spray (or see Loaf Pan Variation).Advertisement
Pulse onion and carrot in a food processor until finely chopped. (Or finely chop them with a knife.)
Heat oil in a large nonstick skillet over medium-high heat. Add the vegetables and cook, stirring occasionally, until tender and most of the liquid has evaporated, 5 to 10 minutes. Transfer to a large bowl and let cool for 10 minutes.
Add sauerkraut, cheese, 2 tablespoons ketchup, caraway seeds and salt to the vegetables; stir to combine. Stir in egg and breadcrumbs. Add ground beef and with clean hands gently knead the vegetable mixture into the meat; do not overmix. Pat the meat mixture into a loaf shape (about 12 by 5 inches) on the prepared baking sheet. Combine the remaining 2 tablespoons ketchup and mayonnaise in a small bowl. Spread on the loaf.
Bake the meatloaf until an instant-read thermometer inserted in the center registers 165 degrees F, about 45 minutes. Sprinkle with chopped pickles. Let rest for 10 minutes before slicing.
Make Ahead Tip: Prepare through Step 3, cover and refrigerate for up to 1 day. Let stand at room temperature while oven preheats; bake until an instant-read thermometer registers 165°F, about 1 hour.
Tip: To make your own fresh breadcrumbs, trim crusts from whole-wheat bread. Tear bread into pieces and process in a food processor until coarse crumbs form. To make fine breadcrumbs, process until very fine. To make dry breadcrumbs, spread coarse or fine breadcrumbs on a baking sheet and bake at 250°F until dry, about 10 to 15 minutes. One slice of bread makes about 1/2 cup fresh breadcrumbs or about 1/3 cup dry breadcrumbs.
Loaf Pan Variation: If you want a more uniform-shaped “loaf” you can bake your meatloaf in a 9-by-5-inch loaf pan instead of on a baking sheet. Coat the pan with cooking spray, pat the meatloaf mixture into the pan and cover with the topping. Bake for about 1 hour. Let stand for 10 minutes in the pan before slicing.
Easy cleanup: Recipes that require cooking spray can leave behind a sticky residue that can be hard to clean. To save time and keep your baking sheet looking fresh, line it with a layer of foil before you apply the cooking spray.
1/2 vegetable, 3 medium-fat meat, 1/2 fat