Czech Sour Lentils with Egg

Rinse the lentils under cold water, place them in a pot, pour in 900 ml water, add the bay leaf and bring to a boil.

Reduce the heat to medium and cook the lentils for 25-30 minutes until tender, making sure they don't turn to mush. Don't discard the cooking liquid — set aside about 200 ml for the roux.

Finely chop the onion. Heat 2 tbsp oil in a skillet and sauté the onion over medium heat for 5-7 minutes until golden.

Add the flour to the onion and, stirring constantly, cook the roux for 1-2 minutes until lightly nutty in aroma, being careful not to let it burn.

Pour 200 ml of the hot lentil cooking liquid into the roux in a thin stream, whisking vigorously to avoid lumps, and simmer for 3-4 minutes until thickened.

Combine the roux with the cooked lentils (remove and discard the bay leaf), add vinegar, salt, black pepper and sugar. Simmer over low heat for another 5 minutes to let the flavors meld.

Heat 1 tbsp oil in a clean skillet and fry the eggs sunny-side up until the whites are just set with runny yolks, or soft-boil them in their shells for 5-6 minutes.

If desired, slice the smoked sausage and pan-fry in a dry skillet until browned.

Serve the lentils hot, topped with an egg, with pickles and fried sausage on the side.