For the meatballs: Preheat oven to 450F degrees.
Drizzle olive oil on a baking sheet. Coat entire surface. Set aside.
Combine the chicken, pastrami, corned beef, sauerkraut, eggs, Swiss cheese, breadcrumbs, caraway seeds, salt and sugar. Mix by hand until thoroughly incorporated.
Roll the mixture into golf ball-sized meatballs (about 1 ounce), firmly packing the meat. Place the balls on the prepared baking sheet, lining them up in snug, even rows to form a grid. The meatballs should be touching one another.
Roast until the meatballs are firm and cooked through (a meat thermometer should register 165˚F), about 20 minutes. Let cool for 15 minutes in the pan or let cool completely before freezing at this point.
For the sandwiches: Use mini rye bread slices or rolls. Assemble with slices of Swiss cheese, sweet and sour red cabbage, and crispy pancetta.