Toss the mesclun with the cubed Asian pear and salad dressing; season with salt and pepper and divide it among 4 dinner plates.
Make sure to remove fat and skin from each duck breast half. Lightly season with salt and pepper.
Heat a non-stick skillet until hot. Add olive oil and duck breasts, skin side down. Saute for to 4 minutes on one side and 2 minutes on the other for very rare duck (or longer if you don't like it rare).
Remove duck to a cutting board. Add spices to skillet with tomatoes and stock. Simmer for 2 to 3 minutes or until reduced. Remove from heat.
Cut the duck in thin diagonal slices and fan them over the salad in the center. Spoon the sauce over the duck and serve, garnished with olives.