Melt butter in medium saucepan. Add onions and sauté until tender.

Add flour and mix until evenly mixed with butter and onion.

Add the beer, mustard, and Worcestershire sauce. Bring to a simmer and remove from heat.

Preheat oven to 350F.

Prepare ingredients. Roughly chop and pull apart corned beef, set aside. Shred cabbage into thin ribbons, set aside.

In a medium sauté pan, heat vegetable oil and sauté cabbage until it starts to become tender. Combine whole grain mustard and apple cider vinegar, add to pan and sauté and additional minute. Remove from heat.

Fry gnocchi from frozen in deep fryer and cook until golden brown. If not using a deep fryer, thaw gnocchi and shallow fry in pan until crispy. Set aside.

In a large bowl, combine corned beef, fried gnocchi, sauteed cabbage, and cheeses.

In a medium sized cast iron skillet, scoop the gnocchi mixture and drizzle with about half a cup or more of the gravy.

Bake in oven until mixture and sauce are bubbly and heated through.

Top with any additional remaining cabbage, garnish with dill pickles.