Preheat oven to 350°F Make a horizontal incision in each chicken breast to form a pocket. Cut the cheese into four pieces, and roll each piece into a cylinder shape. Stuff one into each chicken breast pocket.
Put the flour in one shallow dish, the egg wash in another, and the breadcrumbs in a third. Lightly dredge each piece of chicken in the flour, dip in the egg wash, and then cover with bread crumbs. Refrigerate for15 minutes.
In a large skillet over medium heat, heat the canola oil. Cook the chicken for 3–5 minutes on each side, or until lightly browned. Transfer to casserole dish and bake for 10–15 minutes while preparing the sauce.
In another skillet over medium heat, heat the olive oil. Add the shallot and mushrooms and cook for 3–5 minutes, or until soft but not browned. Add the whiskey and cook for 2–3 minutes, or until slightly reduced, Stir in the half-and-half, season to taste with salt and pepper, and cook for 2–3 minutes longer, or until smooth.
To serve, place a chicken breast in the center of each of 4 plates spoon the sauce over the top. Garnish with the watercress.