Yep, that's what Kasha is. Normally served with a gravy, but I'm not really a gravy hound, so I skip it.

Actual recipe:

toast buckwheat groats in a fry pan for a minute or so. Then add an egg (mixed up). Keep toasting until egg is mostly dry.

(You can choose to saute the onion and mushroom now, if you want. I tend to skip and just throw them in with the stock.)

Transfer buckwheat and egg over to a stockpot. Add appropriate amounts of your favorite liquid (I tend to use chicken stock, plus a bunch of pepper) plus veggies if you didn't saute earlier.

cover, cook.

Make pasta separately. Try to time it so that the pasta finishes when the buckwheat is done cooking.

Mix two together. Nosh until you are full :-)