To make the marinade, combine the vinegars, lemon juice, garlic, shallots, and tarragon. Slowly whisk in the olive oil and bacon fat. Add salt and pepper to taste. Coat chicken inside and out with 1 cup of the marinade and refrigerate, covered, overnight. Reserve the remaining marinade for the vinaigrette.
Preheat the oven to 400 degrees F.
Remove the chicken from the marinade and discard marinade. Season chicken inside and out with 1 1/2 tablespoons seasoning mix. Mix the stuffing ingredients, and stuff it into the chicken. Truss the chicken and roast for 40 minutes. Turn the oven off and allow the bird to continue to cook in the oven for about 20 more minutes.
Season the rice flour with salt, pepper, and 1 tablespoon seasoning mix. Toss the oysters in the flour and shake off the excess. Heat the oil in a shallow saute pan. Brown the oysters in the fat, about 1 minute on each side. Drain on paper towels and immediately season with salt.
Put the butter into a small skillet over medium heat and saute the corn for about 5 minutes. Turn off the heat and add the piquillo peppers, green onions, parsley and reserved marinade to make the vinaigrette. Taste and adjust seasoning with salt and pepper.
Toss the greens with a few tablespoons of the vinaigrette. Top the greens with chicken, oysters, and the remaining vinaigrette. Serve and enjoy.
Blend seasoning mix ingredients. Set aside.
Chef's tip: Marinate the chicken in a sealed plastic bag.