Put the pigeons in a baking dish, with the strip of bacon over each. Place them in a hot (500 degrees F) oven and bake for 5 minutes. Blend the butter and flour over low heat, then add the stock, Kitchen Bouquet, and seasoning and stir until smooth. Add the pigeons and the onions. Let simmer for one hour over very low heat. Then put the pigeons and sauce in a pie dish, cover with a pastry crust, and bake at 500 degrees F for about 12 minutes.