Mix the flour, sea salt, and black pepper in a large bowl. Toss the diced chicken thighs in this seasoned flour until well coated, then shake off any excess.
Dip each piece of floured chicken into the whisked eggs, ensuring they are fully coated, and then roll them in panko breadcrumbs, pressing down lightly to ensure they stick.
Heat the canola oil in a large skillet over medium-high heat. Fry the chicken pieces in batches, cooking each until they are golden brown and fully cooked, about 5-7 minutes per batch. Transfer them to a plate lined with paper towels to absorb excess oil.
In a separate saucepan, mix together the fresh orange juice, granulated sugar, soy sauce, rice vinegar, and chili garlic sauce. Bring this mixture to a gentle simmer over medium heat.
Once simmering, stir in the cornstarch slurry and continue cooking until the sauce thickens, about 2-3 minutes.
Carefully add the crispy chicken to the sauce, tossing gently to ensure each piece is well coated.
Serve immediately, garnished with chopped green onions and a sprinkle of toasted sesame seeds.