Leek & Potato Soup
A creamy, comforting potato soup with onions and spring onions, finished with a splash of milk and optional cream.
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.
Not every ingredient has a checked price at Aldi, Lidl, Asda, Morrisons, Iceland, so they aren't compared here.
Ingredients and prices
Swipe the table to see every supermarket.
| Ingredient | Tesco | Sainsbury's |
|---|---|---|
| Potatoespack 2kg · use 1kg | £1.56£0.08 per 100g | £1.85£0.09 per 100g |
| Onionpack 1kg · use 2 medium | £0.95£0.10 per 100g | £0.95£0.10 per 100g |
| Spring onionsuse 1 bunch (about 100g) | £0.69100g · £0.69 per 100g | £0.69100g · £0.69 per 100g |
| Unsalted butterpack 250g · use 50g | £1.85£0.74 per 100g | £1.85£0.74 per 100g |
| Semi skimmed milkuse 500ml | £0.85568ml · £0.15 per 100ml | £0.85568ml · £0.15 per 100ml |
| Creamuse 100ml | £0.95150ml · £0.63 per 100ml | £0.95150ml · £0.63 per 100ml |
| Cheddar cheeseuse 50g grated | £2.50220g · £1.14 per 100g | £2.85200g · £1.43 per 100g |
| Basket total (full packs) | £9.35 | £9.99 |
| Cost of what this recipe uses | £4.11 | £4.35 |
| Per serving | £1.03 | £1.09 |
From your cupboard
Not in the prices above. Check you have these before you start.
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.
Method
The method is written for 4. For a different number, use the amounts in the table above.
- Peel the 1kg of potatoes and dice them into 2cm cubes. Finely dice the 300g onion and slice the 100g of spring onions, keeping the white and green parts separate for a better garnish.
- In a large stockpot, melt the 50g of unsalted butter over medium heat. Add the diced onion and the white parts of the spring onions, frying for 5-7 minutes until they are soft and translucent, but not brown.
- Add the potato cubes to the pot and stir to coat in the butter. Pour in just enough water to cover the vegetables by, bring to a boil, then reduce heat to low and simmer with a lid.
- Simmer the mixture for 15-20 minutes or until the potatoes are tender when easily pierced with a fork. Remove the pot from the heat and pour in the 500ml semi-skimmed milk and 100ml cream.
- Using an immersion blender, blitz the soup soup until it is completely smooth and creamy. If the soup is too thick, add a splash of water until it reaches your desired consistency.
- Taste the soup and add a generous pinch of salt and black pepper as needed. Stir in half of the remaining sliced green parts of the spring onions to add flavour and colour.
- Ladle the hot soup into four bowls. Top each with the 50g of grated cheddar cheese and the remaining green spring onions. Serve immediately while hot and the cheese is melted.
Tips
- To make this cheaper, use extra milk instead of cream and skip the cheese garnish or use extra herbs.
- To batch-cook, cool leftovers quickly within 2 hours and portion into airtight containers to freeze for up to 3 months.
- To reheat, do in a saucepan over medium heat with a splash of milk until steaming hot throughout; only reheat once.
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.
- Potatoes · about 1kg left
Keep somewhere cool and dark (not the fridge). Use extras for mash, wedges or a traybake later in the week. Use it in: One-pan chicken, potatoes and veg, Chicken and Sweet Potato Tray Bake, Beef & Potato. - Onion · about 700g 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, Egg fried rice, Creamy Tomato & Hidden Veg Pasta Bake. - Spring onions · about 100g 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, Egg fried rice, Creamy Tomato & Hidden Veg Pasta Bake. - Unsalted butter · about 200g left
Check the label: most raw ingredients can be frozen before their use-by date, and cupboard staples keep for months. Use it in: Banana muffins, Ginger Cake, Pad Thai with Chicken. - Semi skimmed milk · about 500ml left
Keep in the fridge and use by the date on the pack; milk can also be frozen. Use it in: Rich Chocolate Mousse, Beef and Ale Pie, Banana muffins. - Cream · about 150ml left
Keep in the fridge and use by the date on the pack; milk can also be frozen. Use it in: Rich Chocolate Mousse, Chicken Stroganoff, Creamy butternut squash soup. - Cheddar cheese · about 350g left
Keep wrapped in the fridge. Grate any extra and freeze it: it melts straight from frozen on pasta bakes and toasties. Use it in: Creamy Tomato & Hidden Veg Pasta Bake, Tuna and Sweetcorn Pasta Bake, Cheesy Bean & Rice Casserole.
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).