I love this warming soup in the colder months. The leeks add a welcome freshness, which goes wonderfully with the creamy butterbeans. So quick and easy to make it comes together in minutes. Especially if you make the croutons ahead of time and keep in an airtight container.
300g sourdough bread, cut into 3cm cubes
60g or 4 tbsp olive oil
5 stalks of rosemary
1 red onion, roughly diced
1-1.2kg, about 6 leeks, whites sliced into 1-2cm rounds, green part shredded
1 litre stock, or 2 stock cubes dissolved in 1 litre hot water
2 tins butterbeans, drained
1-2 tbsps cider vinegar
25g parsley, finely chopped
Lemon zest, optional on croutons or soup
Sea salt flakes and black pepper
Set the oven to 220C/200C Fan /Gas 7. Place a large oven tray in the oven to heat. Toss the bread in 4tbsp of oil and a good pinch of salt in a large mixing bowl. Coat well. Remove the tray from the oven and spread out the oiled bread evenly. Add the rosemary to the mixing bowl and cover in any remaining oil. Return the tray to the oven for 15 minutes. Then give the tray a shake and rotate 180 degrees in the oven, cook for a further 10 minutes. Add the rosemary and cook for a final 5 minutes.
Meanwhile in a pan that will fit everything heat 2tbsp oil over a medium heat. Add the onion and cook for 5 minutes. Add in the leeks and stir to combine. Cook for a further 2 minutes. Then add the stock and beans, bring to a simmer. Once the leeks are tender check the seasoning and add salt and the vinegar to your taste.
Remove the croutons from the oven. The croutons should be crisp and browned. Once cool enough to handle pull the rosemary leaves from the branches and crumble between your fingers over the croutons. Mix to combine and place on a serving dish.
Once ready to serve stir through the parsley and either portion into individual bowls or serve the pan at the table for everyone to get stuck into.