The day before you are planning to serve the meatloaf, begin making the mirepoix by sautéing, in a large frying pan the onions carrots, garlic, and celery over medium heat. Once the vegetables are soft and translucent (about 12 minutes), set them aside to cool.

In the meantime, in a large bowl combine the ground beef and breadcrumbs. You can either put the sautéed vegetables in a food processor and pulse them until they are puréed (or finely chopped if you want more texture)   or you can just skip the food processor and leave them intact.  

If you are processing the vegetables, add the breadcrumbs, salt, pepper, eggs, sour cream, nutmeg, milk and thyme to the food processor. If you leave the vegetables whole, combine all of the ingredients in the bowl with the meat and mix well while you sauté the mushrooms.

Over high heat, in the same pan you have used to sauté the vegetables, sauté thinly sliced mushrooms in the oil remaining in the pan. You do not give want the mushrooms to give up their juices but rather, you are looking for a dry sear. You want them to be brown and crispy, not soggy. Let them cool before adding them to the meat mixture. 

Scoop up the mixture from the bowl and place in a greased loaf pan (10x7x2). I prefer a glass loaf pan. Cover the meatloaf with plastic wrap and refrigerate overnight.

Remove meat and salad ingredients from the refrigerator an hour before you are planing on baking the meatloaf.

Preheat the oven to 350°. Bake in the middle of the oven for one hour or until a meat thermometer registers 135°.

Remove the pan from the oven and let stand for 15 minutes. Carefully drain off all of the juices and turn the loaf pan upside down onto a large platter. Slice and serve in large slices with the Russian salad on top or on the side.

In a large baking pan, toss the quartered potatoes and beets with one tablespoon of olive oil and some salt and pepper. Bake, lightly covered with foil  at 400° for one hour.

Ten minutes before the potatoes and beets are done roasting, toss the carrot sticks with the remaining half a tablespoon of olive oil and bake them for 10 minutes on a small sheet pan until they are crisp-tender.

Dice the potatoes, carrots and beets (discard the onion) into a small one inch dice. While they are still warm, sprinkle the vinegar and salt over the vegetables and toss lightly.  At this point, the vegetables can be refrigerated overnight and removed from the refrigerator an hour before the meatloaf is cooked.

When ready to serve, add the chopped cucumber to the salad. 

In a medium-size bowl, combine the sour cream, mayonnaise, dill, horseradish, salt and pepper and the white balsamic vinegar. Toss with the vegetables, garnish with some fresh dill and serve with the meatloaf.