Preheat oven to 400 degrees F.
Bake potatoes. Halve lengthwise and scoop out flesh, leaving a 1/4-inch shell.
Puree cottage cheese and egg yolk in a food processor. Add potato flesh, scallions, dill, salt and pepper; pulse until just blended. Mound filling into potato skins and place in a baking dish. Bake until heated through, 20 to 30 minutes.
2 starch, 1/2 lean meat