Wash & Chop potatoes into reasonable size, or use baby golds and leave whole. Wash baby carrots, Chop onion, add to crock pot. Some people prefer to add their veggies halfway through the cooking process. I've done both, and it works well both ways.

Lay corned beef fat side up over vegetables. Spread mustard over beef, sprinkle spice packet.

Mix together Brown sugar with about a 1/4 cup of beef stock, pour over beef.

Add beer, rest of the beef broth. Cover, set on low for 10-11 hours for fall apart tender. Can be cooked on low up to 20 hours for fall apart crazy moist meat.

Remove beef from crock pot, let stand for 6mins. Be sure to slice with the grain, not against. You may trim off excess fat.

While beef is resting you can scoop out some of the sauce and add a bit of flour to thicken to use as a gravy. I whip up a honey mustard, and add a bit of gravy to it, as my family loves the flavor.