For the sweetcorn stock, preheat the oven to 200C/400F/Gas 6.
Place the sweetcorn on a baking tray and cook in the oven for 20 minutes. Set aside to cool.
When the sweetcorn is cooled, stand the cobs upright on a chopping board, and cut down as close as possible to the core to remove the kernels. Set aside the kernels and cut the cores of the sweetcorn in half and place them in a large saucepan. Cover them with the water and bring to the boil. Simmer for 20 minutes, then strain into a jug and set aside, reserving both the stock and the kernels.
For the braised sweetcorn and wood pigeon, reduce the oven temperature to 160C/320F/Gas 3.
Season the wood pigeon with salt and pepper and heat a large frying pan.
When the pan is hot, add one tablespoon of the oil and place the pigeons into the hot pan. Cooked until coloured all over, and then place them in the oven for 10-12 minutes. The pigeons are done when the thickest part of the thigh is pierced with a skewer and the juices run clear.
When cooked, place the pigeon crowns on a plate, cover and set aside to rest for 10-12 minutes.
Bring a saucepan of water to the boil and blanch the onions and carrots for 2-3 minutes. Drain and refresh in ice-cold water. Remove the onions and carrots and place on a plate lined with kitchen roll.
Heat a large frying pan and add the remaining tablespoon of oil. Once hot, add the bacon and cook until crisp and golden-brown. Add the onions and cook for a further two minutes.
Cover the bacon and onions with the sweetcorn stock and bring to the boil. Add the sweetcorn kernels and carrots and simmer for five minutes.
Add the butter, season with salt and pepper and set aside in a warm place while you remove the pigeon meat from the carcass.
To serve, pour the sweetcorn and bacon soup into a large serving bowl and arrange the pigeon meat on top.