Mix flour and water together in a bowl until a thin paste forms, adding more water as needed.
Combine flour mixture, chicken livers, cream, onion, eggs, butter, salt, nutmeg and black pepper in a food processor; process until blended and smooth, 30 to 45 seconds.
Transfer liver mixture to three 18cm x 10cm heatproof, disposable containers. Cover containers with foil and place in a roasting tin. Pour enough water into the roasting tin so it is halfway up the sides.
Bake in the preheated oven for 25 minutes. Remove foil and continue baking until cooked through, about 25 minutes. Cool to room temperature. Cover with lids and refrigerate.