Split the guinea fowl in half and place them on a baking sheet.
Layer the bacon over the birds, and sprinkle with seasonings.
Roast them in a preheated 350°F (180°C) oven for 45 minutes.
Remove from oven and remove the bones while hot.
While birds roast puree the blueberries in a food processor, strain to remove pulp and seeds.
Place the juice in a sauce pan and heat to a boil reducing to 2 tbsp (30 ml) of thick liquid.
Place the egg yolks in a double boiler, whisk in the blueberry syrup, slowly whisk in the hot butter forming a thick sauce.
Serve the guinea fowl on a large serving platter with the sauce on the side.