Slow cooker onion soup

Name: Slow cooker onion soup
Prep time: 30 min
Cook time: 2 h
Total time: 2 h 30 min
Cuisine: European, British
Ingredients: 30g/1oz butter, diced; 800g/1lb 12oz onions, thinly sliced; 1½ tsp roughly chopped thyme leaves (optional); 1½ tsp sugar; 1.2 litres/2 pints beef or vegetable stock (made from 2 beef or vegetable stock cubes)

Instructions

Prep:30minCook:2h

This is a super-easy and happily budget-friendly soup with just five ingredients. The slow cooker does all the work here, caramelising and intensifying the flavours of the onion for a rich-tasting result. In September 2023, this recipe was costed at an average of £2.40 when checking prices at three UK supermarkets. It is designed to be made in conjunction with a low-cost store-cupboard.

Updated at: Sun, 24 May 2026 07:32:41 GMT