Place the whole livers onto a baking sheet and pour over the cognac. Mix well so both sides of the liver absorb the cognac. Sprinkle over the garlic and basil, retaining a few leaves, and season, to taste, with salt and black pepper.
Place in the oven for 6-8 minutes, or until just cooked. The livers should look slightly pink inside. Remove from the oven and place into a blender along with 110g/4oz of the butter and blend until smooth.
Check the seasoning then spoon into ramekins.
Place the remaining butter into a saucepan and heat until melted. Pour the clear butter over the surface of the pâté, leaving the milk solids behind in the saucepan. Place remaining basil leaves on the surface of the pâté, and place in the fridge to set.
Serve pâté with melba toast and dressed salad leaves.