Start by peeling the potatoes and carrots. Cut them into small cubes and set aside. If you're using fresh beef, turkey, or chicken, cut it into chunks as well.
In a large pot, bring water to a boil. Add the meat and a pinch of salt. Cook until tender, which usually takes about 1-1.5 hours for beef and less for turkey or chicken. Once cooked, remove from the heat and let it cool.
In the same pot, add the cubed potatoes and carrots to the boiling water. Cook until they are tender, about 15-20 minutes. Don’t forget to add the frozen peas for the last 5 minutes of cooking. Drain and let them cool.
Once the meat is cool enough to handle, chop it into small pieces. In a large mixing bowl, combine the chopped meat, boiled potatoes, carrots, peas, and pickles.
In a separate bowl, mix the mayonnaise, mustard, salt, and pepper. Adjust the seasoning to your taste.
Pour the dressing over the meat and vegetable mixture. Stir gently to coat everything evenly without mashing the ingredients.
Transfer the Beef Salad to your serving platter. Cover it with plastic wrap and refrigerate for at least 2 hours before serving. This allows the flavors to meld beautifully.