Can I use pre cooked Beluga black lentils in the Rapid Ragu or do I buy uncooked green lentils and just add to recipe with 20 min cooking time only?
Nigella's Rapid Ragu (from NIGELLA EXPRESS) is a comforting mixture of meat sauce, made with lamb, and lentils. The lentils help to make this a complete meal in a bowl, without the need for pasta. It also makes it an easy one-pot dish. The uncooked green lentils are added and cooked for 20 minutes. For green lentils this should be sufficient time for them to soften. However older lentils can be dry and hard and would require a longer cooking time, so try to use lentils that have been bought recently from a good supplier. If the lentils are too firm then you could simmer the sauce for slightly longer, adding extra water if needed.
If you would like to use pre-cooked lentils then this is possible but they only need to be added at the end of the cooking time, to warm through for 3-4 minutes. You will need about 150g pre-cooked lentils. You should also omit the water from the recipe as without the lentils to absorb the water the sauce will be too thin. But check the sauce every 5 minutes or so while it cooks and if it looks too dry add a splash of water.