Preheat the oven to 375 degrees. Quarter the chickens. Be careful to leave the breasts covered with skin. Be sure the oyster is left attached to the leg. Remove the thighbone and carefully cut off the drumsticks. Reserve until needed. In a large heavy bottomed stock pot, brown the bones and trimmings from the chickens with the chopped carrots and onions. Pour off the excess fat and moisten with the chicken or veal stock. Add the tomato paste and the bouquet garni. This produces an enriched stock for the sauce. Cook at a low simmer for 40 to 45 minutes, then strain and skim off any excess fat. Next gather all ingredients for the sauce, and measure out the wine and cognac. To assemble the dish, season the chicken with salt and pepper. In a large saute pan heat clarified butter and brown the chicken skin side down. When the chicken is browned, remove it from the pan and into a 375 degree oven. Remove excess fat from the pan, return the pan to the heat and saute the mushroom slices. After 2 minutes add the chopped shallots and saute for a couple of minutes longer. Remove the pan from the heat and add the Cognac. Return the pan to the heat and ignite the Cognac. When the flames have died down add the white wine. Reduce by half. Strain the reinforced stock and skim off any fat that has floated to the top. Add the stock to the mushroom mixture and continue reducing. Add the tomato concasse. When the sauce begins to thicken and coats the back of a spoon, swirl in the butter. Once the butter is incorporated and the chopped chervil and tarragon to taste. To assemble the dish, remove the chicken pieces from the oven. Remove the breastbone from the chicken breast. The advantage to removing the breastbone after cooking is that it helps the breast keep its shape and remain moist during cooking. Since breast tend to cook more quickly than thighs, removing the thighbone and leaving the breastbone intact during cooking ensures that the two are done at the same time. Place 1 piece of white meat and 1 piece of dark on a clean plate and cover with the sauce. Garnish with chopped chervil and tarragon and serve immediately.