Čočka na kyselo, or Czech sour lentil sauce, is a humble dish from Czech cuisine. Well-seasoned and paired with colorful additions like fried egg, sausage, and dill pickles, it becomes a feast for both the eyes and the palate.
Rinse 1 ¼ cups dried lentils under running water in a colander, then transfer them to a saucapan. Add about 4 cups cold water – using about three times the volume of the lentils. Add the bay leaves, cover the pot with a lid, and bring to a boil.
Reduce the heat and cook the lentils according to the manufacturer's instructions until they are tender.
Drain the cooked lentils, reserving the broth in a separate bowl.
Roux with onion:Peel and finely chop 1 medium onion. Heat 1 Tablespoon pork lard in a non-stick frying pan and fry the onions until golden brown. Add 1 Tablespoon all-purpose flour and cook for another 1 minute, stirring constantly. Gradually add the reserved 1 cup lentil broth in batches, stirring well to prevent lumps. Reduce the heat, add 2 bay leaves, and let the onion roux simmer for about 15 minutes, stirring occasionally.
Mix the cooked lentils with the finished roux. Add 1 teaspoon salt, 2 Tablespoons white wine vinegar, and ¼ teaspoon granulated sugar, stirring well. Adjust seasoning if necessary. Remix everything thoroughly, and the dish is ready to serve.
Notes
The basic recipe makes 4 yields.
SERVING: Serve the finished lentils warm, typically accompanied by a variety of side dishes that can be mixed and matched. Common sides include fried onion rings, fried sausage, sunny-side-up eggs (known in Czech as "sázené vejce" or "volské oko"), pickles, rye bread.
STORAGE: Sour lentils should be served immediately after preparation. Over time, the lentils will absorb the vinegar's sourness, causing the dish to become bland.
Classic brown or green lentils are best suited for this dish. Avoid using red lentils, as they easily overcook. Also, do not use canned lentils.
Vinegar is generally added only when the lentils are finally seasoned, not before. White wine vinegar, which has a milder taste, is best. Always add the vinegar carefully, then stir and taste.