Mirepoix is a delicious combination of onions, carrots and celery, very common in french cuisine. Traditionally, the ration calls for the same amount of onions as carrots and celery combined - so a 2:1:1 ratio. This evening, we used 2 medium onions. We sauteed our mirepoix this evening in olive oil, added some salt. Once it was cooked down, the onions were translucents and soft and the carrots and celery were a rich and vibrant colour, we stirred in a cup and a half of beluga lentils and enough water to cover the beans by about an inch. Got the beans up to boiling, then turned the burner down to a gentle simmer and left them, checking them periodically for flavour and doneness. Beluga lentils aren't of the mushy lentil variety - they stay nice and firm when cooked. It's such a simple dish yet so flavourful.
We had simple bowls of it while watching QI, but I imagine it would be nice over rice or mixed into a salad.