Red Lentil Walnut Ragu – Easy & Hearty
Red lentil walnut ragu with rosemary and thyme. A hearty, high-protein vegetarian sauce that works with pasta, polenta, or baked potatoes.
Red lentil walnut ragu is a savoury, herb-forward sauce built on soft red lentils, finely chopped walnuts, rosemary, and thyme. As it simmers, the lentils break down into a thick, silky base while the walnuts add subtle richness and texture.
It’s the kind of dish that’s straightforward to make at home — simple ingredients, high in plant protein, and easy to prepare in a larger batch so you can set aside enough for a few meals.
I find this sort of cooking ideal for the dull grey evenings of February. It’s filling, nourishing, and versatile: good stirred through pasta, spooned over a baked potato, or loosened with a little extra stock and turned into a hearty soup.
Ingredients Breakdown
To make Red Lentil Walnut Ragu, you will need the following ingredients:
- Red Lentils (dry)
- Walnuts (very finely chopped)
- Onion
- Carrots
- Garlic
- Chopped Tomatoes
- Tomato Paste
- Vegetable Stock
- Fresh or Dried Rosemary
- Fresh or Dried Thyme
- Olive Oil
- Soy Sauce, tamari, or Worcestershire
- Salt
- Black Pepper
Step-by-Step Instructions
Preparing the Ingredients
Start by preparing everything before you turn on the heat. Finely dice the onion and carrots as evenly as possible — small pieces help the base cook down smoothly and disappear into the sauce. Mince the garlic finely so it melts into the oil rather than sitting in noticeable chunks.
Rinse the red lentils under cold water until it runs mostly clear, then drain well. Very finely chop the walnuts — aim for a coarse mince rather than large pieces so they integrate into the ragu instead of sitting on top.
If using fresh herbs, strip the leaves from the stems and finely chop them. Discard the woody stems; they won’t soften properly in the sauce.
Build the base
Heat 1 tbsp olive oil in a wide, deep sauté pan over medium heat. Add the finely diced onion and carrot with a small pinch of salt. Cook for 8–10 minutes, stirring every few minutes, until softened and lightly sweet-smelling.
The vegetables should be tender but not browned.
Keep the heat moderate — browning will make the flavour heavier and slightly bitter.
Add the aromatics
Stir in the minced garlic, rosemary, and thyme,. Cook for 30–45 seconds, stirring constantly, until fragrant.
If the pan looks dry, add a small splash of oil to prevent the garlic catching.
Simmer the ragu
Add the rinsed red lentils, tomato paste, chopped tomatoes, vegetable stock, and soy sauce or Worcestershire. Stir well, scraping the bottom of the pan. Bring to a gentle simmer — you’re looking for small, steady bubbles, not a rolling boil.
Cook until thick and tender
Simmer uncovered for 20–25 minutes, stirring roughly every 5 minutes to prevent sticking. The lentils will soften and begin to break down, naturally thickening the sauce.
The ragu is ready when it coats the back of a spoon and holds a soft mound before slowly settling.
Adjust the consistency
If it thickens too quickly, add 2–3 tablespoons of hot water at a time to loosen. If it’s still too thin, simmer uncovered for an extra 3–5 minutes.
For a smoother finish, press some of the lentils gently against the side of the pan with the back of a spoon. Just be aware that doing this will further thicken the ragu.
Add the walnuts
Stir in the very finely chopped walnuts and simmer for 2–3 minutes more. They should soften slightly but still provide subtle texture, as well as turning the ragu from a bright red to a dark brown.
Finish and balance
Season with salt and plenty of black pepper. Add a small splash of balsamic vinegar if you want more brightness.
Rest before serving
Remove from the heat and let the ragu sit for about 5 minutes. It will thicken slightly as it settles, making it easier to spoon over pasta, polenta, or potatoes.
Storage
Allow the ragu to cool fully before transferring to an airtight container. Store in the fridge for up to 4 days — it will thicken as it sits, so loosen with a splash of water or stock when reheating.
For longer storage, freeze for up to 3 months in sealed containers or freezer bags (flattened for easier stacking). Thaw overnight in the fridge and reheat gently on the hob, stirring occasionally and adjusting the consistency as needed.
Red Lentil Walnut Ragu
Ingredients
- 1 tbsp olive oil
- 1 medium onion very finely diced
- 2 medium carrots very finely diced
- 2 garlic cloves minced
- 150 g red lentils dry, rinsed
- 400 g chopped tomatoes
- 1 tbsp tomato paste
- 500 ml vegetable stock
- 60 g walnuts very finely chopped
- 1 tsp dried rosemary or 1 tbsp fresh, chopped
- 1 tsp dried thyme or 1 tbsp fresh thyme leaves
- 1 tsp soy sauce or tamari
- 2 tsp smoked paprika optional
- Salt to taste
- Black pepper to taste
Instructions
- Heat olive oil in a wide, deep sauté pan over medium heat. Add onion and carrots with a pinch of salt. Cook 8–10 minutes until soft, stirring occasionally.
- Add garlic, rosemary, thyme and smoked paprika (if using). Cook 30–45 seconds until fragrant.
- Stir in lentils, tomato paste, chopped tomatoes, stock and soy/tamari. Bring to a gentle simmer.
- Simmer uncovered for 20–25 minutes, stirring occasionally, until lentils are very soft and the sauce is thick. Add a splash of water if needed.
- Stir in finely chopped walnuts and cook 2–3 minutes more.
- Season with salt, black pepper and balsamic (if using). Serve.
Notes
Swaps that work
- No walnuts: Use 40–60 g toasted sunflower seeds, finely chopped, or stir in 1–2 tbsp tahini at the end for richness.
- No soy/tamari: Use 1 tsp vegetarian Worcestershire, or a small pinch of marmite/yeast extract stirred into the stock.
Diet note
The base ragu is naturally vegan and dairy-free. It’s gluten-free if you use tamari (and serve it with gluten-free pasta/polenta/potatoes).Storage
Refrigerate up to 4 days. Freeze up to 3 months. Thaw overnight, then reheat gently with a splash of water/stock to loosen.Yes. You can leave them out, but you’ll lose some richness and texture. For a similar effect, try very finely chopped mushrooms sautéed until browned, or a spoonful of tahini stirred in at the end.
Red lentils absorb a lot of liquid as they cool. Add hot water or stock a tablespoon at a time and stir well until it loosens to a spoonable consistency. Reheat gently rather than boiling hard, which can make it heavier.
They likely need more time or a bit more liquid. Keep simmering gently and add a splash of hot water if the pan looks dry — lentils should be completely soft and breaking down, not holding their shape.
Yes, and it often tastes better the next day. Store in an airtight container in the fridge for up to 4 days, and reheat with a small splash of water to loosen.
Let it cool fully, then freeze in flat containers or freezer bags for up to 3 months. Thaw overnight in the fridge and reheat slowly, adding a little liquid if needed.
It works well over polenta, mashed potatoes, or baked sweet potatoes. You can also thin it slightly with stock and serve it as a thick lentil soup.
This was absolutely delicious and so easy to make, I had all of the ingredients in my store cupboard. This was a very cost effective meal, definitely one to make again.