Marinate chicken by cutting breasts into 1-inch cubes and pouring tangerine juice over them; cover and refrigerate for 2 hours.

Prepare sauce by combining tangerine juice, soy sauce, hoisin sauce, red chili paste, brown sugar, garlic and ginger pastes, and red pepper flakes in a saucepan; whisk and simmer for 10 minutes.

Coat chicken by whisking eggs, cornstarch, salt, and pepper in a bowl; coat each marinated chicken piece with this mixture.

Fry chicken in hot oil at 300°F for about 5 minutes until golden brown; use a slotted spoon to drain excess oil.

Thicken the sauce by preparing a cornstarch slurry with 1 tablespoon of cornstarch and 2 tablespoons of water, then stir into the simmered sauce.

Combine crispy fried chicken, tangerine segments, and diced bell pepper in the sauce; toss together on low heat for about 2 minutes.

Garnish and serve hot over rice or noodles, topped with green onions and optional sesame seeds.