i’ve been making lentil soup for years but never really had a favorite recipe, just a general sense of what ingredients i tended to use. when i went to write down a recipe to share here, it turned out i was a little unclear on even what ingredients i liked to include.
my first keep-track-of-ingredients test batch included sausage, since it seemed obvious that sausage would be tasty. except, it wasn’t. not really anyway. it certainly didn’t add enough flavor to justify giving up “vegetarian” status. so, scratch the sausage.
i’ve been on a mushroom kick lately (here and here, for starters) so when the first trial batch of soup lacked umami flavor and depth, i figured i’d sauté some mushrooms for batch two. sautéed mushrooms turned out to be a keeper.
another fun learning experience for me was that tomato paste really makes a difference in the finished soup. in my first batch, i skipped it because i had the sausage and maybe i just forgot or didn’t want to open a new can or wasn’t sure it mattered. well, it does. batch two (no sausage, yes tomato paste) was noticeably much better than its paste-less brethren. tomato paste, yes. decided.
(and don’t fret about using just 2 tablespoons out of a can of tomato paste; it keeps forever-ish* in a ziploc bag in the freezer, ready for you to pull off a chunk next time you need a tablespoon of it. even when frozen, it’s still soft enough to break a piece off and after thawing on the counter for one minute, you can easily measure it.)
finally, i knew this ingredient was important but i just want to highlight it here in case you’re unfamiliar with the concept and think it sounds weird. tossing the rind from a hard cheese such as pecorino romano or parmesan into the soup pot makes for extra yummy lentil soup. if you want to keep the soup vegan/dairy free, you can certainly leave it out but if you have a cheese rind and you’re cool with dairy, i recommend it.
i actually stockpile cheese rinds in a ziploc bag in the freezer. they tend to accumulate over the summer when i’m not making soup and then i make my way through my stockpile over the course of the winter. basically, i am a squirrel. but instead of acorns, i have a freezer full of cheese rinds and tomato paste. you should too. we’ve got more soup-ing to do over the next few months.
*”forever-ish” is neither a real word nor a foodsafety.gov sanctioned length of time to keep something you intend to eat. but it’s mostly true.
- 1 tablespoon olive oil
- 16 oz. (454 g.) carrots, thinly sliced into coins (and cut in half if they are thick)
- 1 yellow onion, diced
- 4 oz. (113 g.) white button mushrooms, sliced
- 7 large cloves of garlic, thinly sliced
- 2 tablespoons tomato paste
- 28 oz. (794 g.) crushed plum tomatoes (i use no salt added)
- 70 oz. (1984 g. or 2 ½ cans worth) water
- 2 bay leaves
- 1 teaspoon dried rosemary
- ½ teaspoon dried thyme
- ½ teaspoon dried sage
- 16 oz. (454 g.) dried brown lentils (see notes), picked over for stones/odd bits
- rind from pecorino romano, parmesan, or any hard cheese, optional but recommended!
- grated pecorino romano, parmesan, etc. for serving, optional
- heat the olive oil in a dutch oven or large, heavy bottom soup pot over medium heat. add the carrots and sauté for a few minutes, just to give them a head start. add the onion and sauté for a few minutes, until the onions are beginning to soften. as you’re sautéing, keep an eye on the heat so that the vegetables don’t burn. some brown fond on the bottom of the pan is good but black and burned is bad. dutch ovens retain heat so well that you may need to turn the heat down as you go.
- add the mushrooms and sauté until the mushrooms are golden brown and the onions are soft and translucent. the carrots should be pretty soft by now too (don’t worry if they aren’t totally soft yet though). add the garlic and sauté, stirring constantly, for 30 seconds until the garlic is fragrant. add the tomato paste and continue stirring and sautéing for another 30 seconds.
- add the crushed tomatoes, water, spices, lentils, and cheese rind. stir everything around until it is well combined.
- simmer on lower heat, partially covered, until the lentils are cooked through. the lentil package may offer guidance but the length of time ultimately depends on the age of the lentils and other difficult to discern factors so just start tasting them around the 25 minute mark but keep in mind they may need up to 45 minutes. stir the soup periodically, especially the bottom so it doesn’t burn. you may need to add more water if your lentils take a while to cook or you like your soup thinner.
- when the lentils are done, remove the pot from heat. fish out the bay leaves and cheese rind, or at least make sure you don’t serve them. i do usually leave them in the leftover soup that i’m storing and just watch out for them when i’m dishing out soup.
- i like this soup best with some grated cheese, a hunk of crusty bread, and some extra virgin olive oil to dip it in but you do you.
the soup is vegan if you leave out the cheese rind and vegetarian either way (if you’re a really strict vegetarian, then you already know that some cheeses are not vegetarian and you’ve already found a favorite that is).
i’m not getting paid to say it but i have been impressed with trader joe’s brown lentils. they do a much better job holding their shape when fully cooked than goya, my previous go-to. just in case it’s helpful…
this soup lasts about a week in the refrigerator or you can freeze it. it keeps well in the freezer and reheats beautifully.