Slow Cooker Lentil Chilli
Hearty, budget-friendly lentil chilli perfect for batch cooking and freezing.
Allergens: none of the 14 main allergens in the usual versions of these ingredients. Brands differ, so always check the labels on what you buy.
Per serving (approx.): 45g carbs · 8g sugars · 18g fibre. Diabetes-friendly: no added sugar, 45g carbs or less and plenty of fibre per serving. Estimates for carb counting, not medical advice. If you have diabetes, follow your GP or dietitian's advice.
Not every ingredient has a checked price at Aldi, Lidl, Sainsbury's, Morrisons, Iceland, so they aren't compared here.
Ingredients and prices
Swipe the table to see every supermarket.
| Ingredient | Asda | Tesco |
|---|---|---|
| Red lentilspack 500g · use 250g | £2.00£0.40 per 100g | £2.10£0.42 per 100g |
| Onionpack 1kg · use 150g | £0.98£0.10 per 100g | £0.95£0.10 per 100g |
| Garlicnot compared | – | £1.90 |
| Chopped tomatoespack 400g · use 800g | £0.47£0.12 per 100g | £0.47£0.12 per 100g |
| Kidney beansnot compared | – | – |
| Chilli powderpack 100g · use 2 tsp | £1.00£2.27 per 100g | £1.00£2.00 per 100g |
| Vegetable stock cubepack 100g · use 1 | £1.25 | £1.00£0.10 per 100g |
| Basket total (full packs) | £5.70 | £5.52 |
Not compared (a price wasn't found at every shop, so it isn't in the totals): Garlic, Kidney beans.
Prices checked on 3 October 2026 from each supermarket's own listing or a price-comparison site. Each shop's unit price (or pack size) is shown under its price, and "cost of what this recipe uses" compares like with like (tap a price to see its source). Cheapest in each row is ticked. Prices, offers and pack sizes change; loyalty-card prices are not included unless stated.
You'll also need (from the cupboard): 1 tbsp vegetable oil, salt and freshly ground black pepper, 500ml boiling water (for stock).
Method
The method is written for 6. For a different number, use the amounts in the table above.
- Peel and finely dice the 150g onion. Peel and mince the 2 garlic cloves. Weigh 250g red lentils and rinse them in a sieve under cold running water until the water runs clear. Drain the 400g tin of kidney beans and rinse well. Crumble the vegetable stock cube into a measuring jug and dissolve it in 500ml boiling water.
- Heat 1 tablespoon vegetable oil in a large frying pan over a medium heat. Add the diced onion and cook for 5–6 minutes, stirring occasionally, until softened and translucent but not browned. Add the minced garlic and cook for a further 30–60 seconds until fragrant, taking care not to let it burn.
- Stir in the 2 tsp chilli powder and cook for 30 seconds to release the aroma. Add the rinsed lentils, the 800g chopped tomatoes, the drained kidney beans, and the 500ml hot vegetable stock. Stir everything together and bring to a gentle simmer for 2–3 minutes so the flavours start to meld.
- Transfer the entire mixture into a 4.5–5 litre slow cooker. Put the lid on and cook on the low setting for 6 hours. The chilli is ready when the lentils have completely broken down, the sauce has thickened to a rich, hearty consistency, and a spoon drawn through the centre leaves a clean trail.
- About 15 minutes before the end of cooking, taste the chilli and season with salt and freshly ground black pepper — start with ½ tsp salt and ¼ tsp pepper, then adjust to your preference. If the chilli looks too thick, stir in a splash more hot water; if too thin, leave the lid off for the last 30 minutes.
- Once cooked, give the chilli a thorough stir to distribute the lentils evenly. Ladle into bowls and serve hot, topped with a dollop of soured cream or yogurt, a scattering of chopped fresh coriander, and a wedge of lime on the side if you like.
- To store leftovers: cool the chilli to room temperature within 1–2 hours (spread in shallow containers to speed cooling), then cover and refrigerate. Eat within 48 hours. For longer storage, portion into airtight containers and freeze as soon as cooled; use within 3 months for best quality.
Tips
- Swap half the lentils for a 400g tin of green or brown lentils (drained) to stretch the meal further and add texture — they’re often cheaper per kg than red lentils.
- Batch-cook a double quantity in a 6.5L slow cooker; portion into 6 individual containers once cooled. Freeze 4 portions and keep 2 in the fridge for the next 2 days — this gives you six ready meals for the week.
- Reheat from fridge or defrosted (thaw overnight in the fridge) in a microwave or saucepan until steaming hot throughout (at least 75°C). Only reheat once; discard any leftovers after reheating.
Nothing wasted: your leftover ingredients
Supermarkets sell set pack sizes, so you'll have some ingredients left. Here's how to keep them, and other recipes here that use them up.
- Red lentils · about 250g left
Dried: keep sealed in the cupboard for months. Opened tins: move to a covered container in the fridge, use within 2 days, or freeze. Use it in: Lentil and vegetable soup, One-Pot Creamy Tomato & Lentil Pasta, Creamy Lentil & Spinach. - Onion · about 850g left
Chop the rest and freeze it flat in a bag: it cooks straight from frozen in soups, curries and sauces. Whole onions keep for weeks somewhere cool, dark and dry. Use it in: Chilli con carne, Cheesy Bean & Veg Quesadillas, Egg fried rice.
Storing leftovers
Cool leftovers and put them in the fridge or freezer within 1–2 hours. Eat fridge leftovers within 2 days, or freeze them. Defrost in the fridge and reheat only once, until steaming hot all the way through (Food Standards Agency guidance).