1. Start by heating a large non-stick pan – a medium heat will do. Then, add the butter and oil, allowing it to melt.
2. Tip in the garlic, celery and onion to sauté for 10 minutes until soft. Next, add the fresh rosemary and bay leaves, along with a good grind of black pepper, cooking them out for a few more minutes.
3. Now for the main stars of the stew. Tumble in the chunks of squash as well as the lentils. Give them a good stir, ensuring everything is coated before pouring in the stock.
4. Bring the stew to the boil and let it gently simmer for 35 minutes, or until the squash is tender. When you’re happy, turn off the heat and add in the fresh parsley, lemon juice and a generous pinch of salt.
5. Serve with a drizzle of sour cream or a dollop of natural yoghurt (and a hunk of bread if you’re extra hungry).