2 large ribs celery, diced

1 small yellow onion, diced

1/4 teaspoon salt, plus additional to taste

1 cup red lentils

4 cups water or low-sodium broth

1 whole bay leaf

2 tablespoons lemon juice from 1/2 large lemon

Olive oil, yogurt or other topping, to serve

In a medium (2- to 3-quart) saucepan or Dutch oven, heat the olive oil over medium heat. Add the carrot, celery, onion and 1/4 teaspoon salt. Stir to combine, then cover and let the vegetables sweat until the onions are soft and translucent, about 5 minutes.

Add the lentils, the water or broth, and the bay leaf. Bring up to a boil, and then turn the heat down to low and let simmer, covered, until the lentils begin to fall apart, about 20 minutes.

Turn off the heat, stir in the lemon juice, and add salt to taste. Ladle into bowls and serve. Leftovers will keep refrigerated for 5 days.

Recipe notes

To perk up the soup just before serving, top it with a drizzle of peppery olive oil, a dollop of plain yogurt, a sprinkle of sumac, or a spoonful of gremolata.

This recipe is pared down to just the basics -- you can certainly add a teaspoon of garam masala, Italian herbs or any other seasoning blend to spice things up a bit if you like. Just add the spices in along with the lentils and broth.

(Coco Morante is a writer for TheKitchn.com, a nationally known blog for people who love food and home cooking. Submit any comments or questions to kitchn@apartmenttherapy.com.)