3 ½ lb beef brisket.
5 carrots, peeled and cut into one-inch chunks.
5 medium red potatoes, unpeeled, quartered.
3 medium onions, sliced.
1 cup of ketchup.
1 cup of water.
2 tablespoons of onion, minced.
2 tablespoons of cider vinegar.
1 tablespoon of horseradish.
1 tablespoon of mustard.
Salt and pepper.
Mix together the ketchup, water, minced onion, cider vinegar, horseradish, mustard and pepper.
Place the brisket in a shallow glass baking dish and pour the marinade over. Cover and refrigerate overnight.
Preheat your oven to 375°F (190°C).
Scatter the sliced onions on top of meat.
Cover and bake for 3 hours.
Add the carrots and red potatoes. Cover and keep baking until the beef and the vegetables are tender (60 - 75 minutes).
Add salt to taste.
Cut the beef meat into slices and serve, using the juices as sauce.