Potato and Carrot Babka Recipe
Optional soufflé topping:
Heat a large skillet over medium heat and cook the bacon, stirring occasionally until the fat has rendered and it's nice and crispy (about 15 minutes). When it's crisp, take the bacon out of the grease and set aside. Use some of the rendered fat to grease a 13- x 9-inch casserole dish and set that aside.
Sauté the onion in the remaining fat until it's fully softened and starting to caramelize, about 20 minutes (adjust the heat, as needed, if it colors before it's softened). While the onions are cooking, preheat your oven to 400°.
When the onions are cooked, set them aside and let cool slightly while you prepare the rest of the babka. Combine grated potatoes, carrots, kefir, eggs, salt and caramelized onions in the food processor and pulse until the shredded potato and carrot are finely chopped and the ingredients are mixed together (just a few pulses). Stir in rendered bacon.
Pour the mixture into your prepared casserole dish and bake for 2 hours—covered for the first hour, uncovered for the second. Serve warm.
If you're going for the soufflé topping, when the babka is done, vigorously whisk together the mayonnaise and egg until well combined. Take the babka out of the oven and evenly spread the mayonnaise mixture over the top. Place the casserole under the broiler, and broil 3 to 5 minutes, or until the mayo has puffed up and is golden-brown and set. Remove from the oven, and let cool slightly before serving.
From Kachka: A Return to Russian Cooking (Flatiron Books) by Bonnie Frumkin Morales with Deena Prichep.