Cut pork into bite-size pieces and marinate for 30 minutes in mixture of soy, vermouth, garlic, ginger, and 2 tablespoons oil. Set aside.
Meanwhile, make the sweet and sour sauce:
In a medium saucepan, combine all ingredients except the cornstarch mixture, blend well and bring to a boil. Add cornstarch mixture. Reduce heat and simmer, stirring frequently until thickened. Be sure and bring your sauce to a boil before adding the cornstarch, otherwise the sauce may retain an unpleasant starchy taste.
Heat oil in a Dutch oven to 350 degrees F.
Remove pork pieces from marinade and roll in cornstarch to coat well. Deep fry in hot oil until golden brown and crispy.
In a large saute pan, heat 2 tablespoons oil on medium-high heat. Stir-fry red and yellow pepper and diced onion for 2 minutes, then add sweet and sour sauce and fold in fried pork. Let simmer for 2 minutes, arrange on serving platter and garnish with long strips of green onion and toasted sesame seeds.