Mix all ingredients and allow to sit while you make the rest. Can be made a day or two ahead.

Submerge the red onion in white vinegar and allow to stand about 10 minutes. Can be made the day ahead. Drain off vinegar before using.

Cut the loaf in half horizontally. Hollow out some of the soft centre of the top and bottom leaving them ¼ to ½" deep.

Spread half the olive salad on the inside of top and half on the bottom of the bread. The bread will absorb some of the juices and tenderize a bit overnight.

Layer in concentric circles to the bottom of the loaf - add a layer for each of Kielbasa slices, sweet pepper, Kielbasa, red onion. For the top half layer Swiss cheese, Hungarian Salami, sweet pepper, Swiss cheese, Hungarian Salami. (Order of layers is not critical as long as you alternate).

Quickly and carefully flip the top half of the sandwich onto the bottom.

Wrap tightly in plastic wrap. Weight down with a cast iron skillet or some other weight and allow sandwich to rest in the fridge overnight or up to 2 days.

When ready to serve, remove wrap and slice into wedges. Serve wedges wrapped in parchment paper.