Parboil cabbage and separate the leaves.
Slice off part of the heavy stalk of each leaf by slicing parallel to the leaf (do not cut into the leaf).
Grate potatoes, small inner leaves of cabbage, and one of the onions.
Mix together.
Add rice, dill, and black pepper.
Beat egg whites until frothy and add to potato mixture.
Set aside two or three of the largest leaves.
Fill each remaining cabbage leaf with approximately 2 Tbsp of the potato mixture.
Fold up bottom of leaf, then fold in the sides, and roll up.
Secure with toothpick if necessary.
Slice the reserved leaves and line the bottom of crock pot with them.
Slice second onion and layer on top of cabbage.
Add tomatoes, apple, and ginger.
Place rolled stuffed cabbages into pot.
Cook at low heat for 4 to 5 hours.