For the sweetcorn purée, heat half the butter in a large frying pan and add the corn. Cook for 1-2 minutes then add the stock and simmer for 3-4 minutes. Stir in the remaining butter and the cauliflower and blend until smooth. Set aside.
For the guinea fowl Maryland, preheat the oven to 180C/160C Fan/Gas 4.
Heat a deep-fat fryer to 180C, or alternatively half fill a large deep saucepan with vegetable oil and heat it until a cube of bread turns golden-brown within 1 minute of being added to the oil. (CAUTION: hot oil can be dangerous. Do not leave unattended.)
Combine the spices and rub them into the guinea fowl. Heat an ovenproof frying pan and, once hot, add the meat and cook until golden-brown all over. Deglaze the pan with the brandy by stirring the bottom to loosen any charred bits of meat. Cook for a few minutes to allow the alcohol to burn off. Add the chicken stock to the pan, cover with aluminium foil and finish in the oven for 8-10 minutes.
In a frying pan, heat a knob of butter and fry the sweetcorn until the butter is brown. Stir in the birch syrup. Keep warm until ready to serve.
With the skin on, use kitchen paper to ensure the banana is dry. Deep fry the banana, with the skin on, until it is brown and bubbling then remove from the fryer. Cut in half widthways.
When the guinea fowl is cooked, remove it from the pan and set aside to rest. Put the pan on the hob and heat until the volume of liquid has reduced to a sauce. Remove from the heat and whisk in the remaining butter and cream to finish.
To serve, carve the breasts and serve with the toasted corn, banana halves and sweetcorn purée. Spoon over the sauce and garnish with watercress.