Colder nights push households back to the hob, where one cheap, cheerful pot has become the midweek fallback across Britain.
As grocery budgets tighten, a four-ingredient lentil soup has quietly emerged as a dependable autumn staple. It takes a short shop, a single pan and around an hour on the stove. The result is a week’s worth of lunches that taste like comfort and cost less than a bus fare.
Why four ingredients are enough
This pot leans on humble produce that rarely lets you down. Onion brings depth, carrot adds sweetness, leek provides gentle aromatics. Red lentils do the heavy lifting with body, fibre and a modest hit of protein. No dairy. No fancy kit. No fuss.
Four ingredients, one pan, seven bowls. That’s the quiet win families need when the heating goes on.
The core trio of veg
Onion, carrot and leek form a classic base. They soften into a savoury foundation that turns simple lentils into something satisfying. Dice them small for a smooth blend or chunkier if you prefer texture. A little oil helps them sweat without catching.
The lentil that does the heavy lifting
Red lentils break down as they cook, thickening the broth without cream. They cook quickly, carry spices well and give a silky feel when blended. A handful goes a long way, so the pot stretches across several days.
Your 49p-per-bowl breakdown
Shoppers buying at a discount supermarket report a typical basket around £3.48, producing six to seven portions. That lands near 49p a bowl, seasoning included. Prices vary by store and region, but the pattern holds: small spend, many meals.
| Item | Quantity used | Typical cost | Cost in the pot |
|---|---|---|---|
| Onion | 1 medium | £0.18–£0.25 each | £0.20 |
| Carrots | 5 medium | £0.55 per 1kg bag | £0.30 |
| Leeks | 2 medium | £1.20–£1.40 per pack | £1.30 |
| Red lentils | 100g (from a 500g bag) | £1.60–£1.90 per 500g | £0.35 |
| Seasoning | Salt, pepper, stock cube | Kitchen staples | £0.15 |
| Approximate total | 6–7 portions | — | £3.48 |
Under £3.50 turns into a week of warm lunches. That’s the kind of maths that helps in November.
Method that fits a busy week
- Roughly chop one onion, five carrots and two leeks.
- Soften in a splash of oil with a pinch of salt for 8–10 minutes.
- Stir in 100g red lentils and toast for 1 minute.
- Cover with boiling water or light stock. Start with 1.2–1.5 litres.
- Simmer gently until the carrots and lentils are tender, around 50–60 minutes.
- Season to taste. Add black pepper and a pinch of cumin if you like.
- Blend smooth with a stick blender or keep it chunky for more bite.
Blend for velvet, or leave it rustic. The pot works both ways, and both reheat well.
Taste tweaks and swaps
The base is forgiving. Use what you have and keep waste out of the bin. A few additions change the mood without adding cost.
- Extra veg: celery, sweet potato, potato, butternut squash, bell pepper.
- Spices: cumin, smoked paprika, turmeric, chilli flakes, bay leaf.
- Herbs: parsley or thyme at the end for freshness.
- Texture: add a handful of oats for extra body, or keep more liquid for a lighter bowl.
- Finish: a squeeze of lemon or a swirl of yoghurt if you have it.
Nutrition, storage and safety
The mix brings plenty of fibre, steady carbs and a modest protein lift. The lentils support fullness, while carrots and leeks supply colour and micronutrients. It’s gentle, filling food that suits workdays and early dinners.
- Cooling: let the pot cool within two hours, then chill in sealed tubs.
- Fridge life: up to three days. Reheat until steaming hot.
- Freezer: portion and freeze for up to three months.
- Defrosting: thaw in the fridge overnight or reheat from frozen with a splash of water.
Energy use and time saving
On a low burner the soup needs a gentle bubble, not a hard boil. A one-hour simmer on an electric hob can use around 0.5–0.8 kWh, depending on ring size and pot. At typical unit rates, that adds roughly 15–25p to the batch. The figure falls if you cover the pan and keep heat low.
Busy week ahead? Try a slow cooker on low for three to four hours. The lentils soften without supervision, and the running cost tends to be modest.
Set it up after breakfast, and you’ve got hot soup waiting when the school run is done.
What readers are asking
Can I keep it gluten free?
Yes. Use a gluten-free stock cube or just season with salt, pepper and herbs. The base ingredients are naturally gluten free.
Will children eat it?
Many do. Keep seasoning light and blend smooth. A buttered slice of bread helps younger eaters. For toddlers, thin it a little with water.
How do I make it higher in protein?
Add 50g more lentils, tip in a drained tin of cannellini beans, or serve with a cheese toastie. Each approach lifts protein without much cost.
Make the most of the pot
Pair the soup with croutons baked from day-old bread. Brush cubes with oil, season, and toast in a hot oven for eight minutes. You use leftovers and add crunch without spending extra.
If you batch-cook on Sunday, portion the pot into seven tubs straight away. Write the date on the lid. Two go in the fridge, five into the freezer. That small ritual prevents midweek panic buys and keeps your 49p promise intact.
Made a batch on Sunday—kids actually ate it! Added a squeeze of lemon at the end and it slapped 😋 Total spend was £3.60 here, still a bargain.
Honest question: does the 49p include the energy cost? On my electric, an hour simmer plus blending nudges it past 60–65p a bowl.