St. Patrick's Day Corned Beef Dinner

Acquire all necessary ingredients.

Prepare the main dish by placing corned beef in a 6-quart Dutch oven and adding sufficient water to cover the meat by approximately two inches. Bring the mixture to a rolling boil, occasionally removing excess fat from the surface with a spoon. Gradually decrease the heat to a lower setting, cover the pot, and let it simmer for two hours.

Arrange the cabbage, potatoes, onions, and carrots around the corned beef in a circular pattern. Return the pot to a boil, then reduce the heat to a lower setting once more, cover it again, and let the vegetables cook until they are tender and the beef can be easily pulled apart with a fork, approximately 40 minutes.

Transfer the corned beef to a serving platter. Use a slotted spoon to carefully remove the vegetables and arrange them around the beef on the platter. Reserve 1 1/2 cups of the cooking liquid for later use in making a sauce.

Create the sauce by melting butter in a small saucepan over medium heat. Whisk flour into the melted butter until it is fully incorporated and forms a smooth, bubbly mixture. Add the reserved cooking liquid and vinegar to the saucepan, stirring frequently as it cooks until the sauce has thickened slightly, approximately four minutes.

Remove the saucepan from the heat and whisk in sour cream and mustard until well combined.