Preheat oven to 375 degrees Fahrenheit.
On a baking sheet lined with parchment paper, place proscuitto. Place in oven for 5-7 minutes until crisp.
Season outside of duck breasts with salt and pepper. In a fry pan over medium high heat add a little vegetable oil and sear off duck breasts. Remove duck from pan and drain off excess fat. Add 1/3 cup soy, sherry, oyster sauce, brown sugar and all spice. Boil for 4 minutes and add duck breasts. Continue to cook for 2 minutes until glazed. Place in oven until desired doneness. Allow to rest for 5-10 minutes.
Season outside of chicken breasts with salt and pepper. In a fry pan over medium high heat add a little vegetable oil. Place chicken breasts, skin side down, and cook until skin is golden brown. Turn breasts over and place in oven. Cook until desired doneness.
In a stainless steel bowl whisk together 6 Tbsp soy sauce, rice vinegar and garlic. Finely chop Chinese barbequed duck breast and add to vinaigrette along with lettuce. Toss to coat.
On thinly slice rye bread place crispy proscuitto. Add a thin slice of chicken breast and duck breast. Spoon a little duck glaze over. Top with lettuce/barbequed duck mix and another slice of rye. Serve immediately.