Wash off any seasoning on the corned beef.

Place corned beef in a pot with onion and garlic.

Add juice from the corned beef if it's not already seasoned.

Add water to cover the beef.

Boil at a low temperature for 20 minutes per pound.

Boil with salt and pepper until halfway through cooking time.

Remove meat from the pot.

Cut off and dispose of all the fat from the meat.

Dice the meat into small pieces.

Return the diced meat to the pot.

Wash, peel, and dice the potatoes.

Add the potatoes to the pot.

Continue to boil until potatoes are done.

Drain the pot, reserving the cooking liquid (pot liquor).

In a separate bowl, mash the potatoes and beef together.

Add milk, butter, salt, and pepper to taste.

Blend well until a smooth texture is achieved.

If needed, add reserved pot liquor for additional liquid.

Serve hot.