01 -
In a large saucepan, heat the olive oil and butter. Add the roughly chopped celery and fry for a few minutes until it begins to soften.
02 -
Add the chopped garlic and red lentils to the pan. Continue to fry for another minute or two, stirring to coat the lentils in the oil mixture.
03 -
Pour in the stock and bring to a simmer. If using cheese rinds instead of grated cheese, add them at this point. Cover with a lid and simmer for about 20 minutes, until the lentils are soft and breaking down.
04 -
Add the broccoli or other vegetables of your choice to the soup. Continue to cook for another 5-10 minutes until the added vegetables are tender.
05 -
Remove the soup from heat and blend until smooth using a stick blender directly in the pot. Alternatively, transfer to a jug blender - if using this method, remove the central bung from the lid and cover with a tea towel to allow steam to escape safely.
06 -
If the soup is too thick, add a little more hot stock to reach your desired consistency. Add the grated hard cheese and stir until it melts completely into the soup.
07 -
Taste the soup and season with salt and pepper as needed. Serve hot, perhaps with some crusty bread on the side.