I went to bed on Wednesday night with a tupperware full of leftover kasha varnishkes in the fridge from Rosh Hashanah dinner #1. That night, I dreamed of a kasha varnishkes frittata. So I made it, and it served quite well at Rosh Hashanah dinner #2. —linzarella
Preheat the broiler. In a large, oven-proof, preferably cast iron skillet, melt the butter over medium heat. Meanwhile, beat together the eggs, thyme, cream or creme fraiche, salt, and pepper until just combined.
Add the leftover kasha varnishkes to the pan and toss to coat in the butter. Then add the egg mixture, and use a spatula to help it distribute evenly among the kasha varnishkes.
Cook for five minutes or so, until it's starting to set along the edges. Finish under the broiler for a few minutes, until browned and crispy on top.
Melt your fat of choice over medium heat. Add the onions, and cook until caramelized. Turn the heat to medium-high, add the mushrooms and a pinch of salt, and cook until the mushrooms are soft and silky. Add a splash of water if they need some help cooking.
Bring a large pot of heavily salted water to boil for the pasta. In another saucepan, boil 1 cup of water, then add the kasha and a pinch of salt. Cover and simmer 15 minutes.
Cook and drain the pasta. In a large bowl, combine the mushrooms, onions, pasta, and kasha, adding a little more fat, salt, and pepper.