In a medium mixing bowl combine sauerkraut, green onions, and caraway seed.
Finely chop 2 slices of the ham; stir into sauerkraut mixture.
For sauce, in a small mixing bowl stir together mayonnaise or salad dressing, 2 tablespoons milk, and the mustard.
Add 1/4 cup of the sauce to the sauerkraut mixture; mix well.
Place one fourth of the sauerkraut mixture on each remaining ham slice.
Roll up each slice from one side.
Place rolls seam side down in a 10x6x2 inch baking dish.
Bake, covered, in a 375° oven about 20 minutes or till heated through.
Stir 1 teaspoon milk into remaining sauce.
Spoon over ham rolls before serving.