Kreplach, Kreplach, I'd rather have that than a prune danish...
1. Any places where you can buy frozen Kreplach?
2. Around the Washington DC area, any good places that have it, eg serve it?
3. "Best" Kreplach recipes, or source for them?
I can only respond to #3. "Love and Knishes" is a great source of simple make-your-own recipes for basics like soup nuts and farfel. I use her kreplach recipe, substituting 70% whole wheat flour and when making fleishig kreplach (I like turkey to put in chicken soup - good flavor but doesn't overwhelm your broth), I do not cook the meat first. Feel like a bit of a cheater, but cooked ground meat is bumpy, and those bumps tend to tear through the dough.
Simmer kreplach in water or broth. Don't overcrowd. Turn once.
Cooked kreplach freeze well.
When you do find a place that sells them frozen (Shalom's maybe in Wheaton/Silver Spring) go with Barney's brand, best spiced meat inside (not flavorless like some other brands)