In a mixing bowl, whisk together all sauce ingredients: chicken broth, soy sauce, rice vinegar, hoisin sauce, sugar, tomato paste, sesame oil, cornstarch, and sriracha. Set aside.

Pat chicken pieces dry with paper towels on cutting board. Season with salt and pepper.

Set up breading station: In one bowl combine cornstarch and flour. In another bowl, place beaten eggs.

Dip each chicken piece in egg, then dredge in cornstarch mixture, coating thoroughly. Place on a baking sheet lined with parchment paper.

Heat 2 inches of oil in deep fryer or heavy-bottom pot to 350°F. Working in batches, fry chicken for 4-5 minutes using tongs or wire rack until golden brown and crispy. Drain on paper towels.

Blanch broccoli: Add broccoli florets to boiling water for 2 minutes, then drain and set aside.

Heat 1 tablespoon oil in grill or cast iron skillet over medium-high heat. Add garlic, ginger, and dried chilies. Stir-fry for 30 seconds using a wooden spoon until fragrant.

Pour sauce into skillet and bring to a simmer. Cook for 2-3 minutes, stirring with whisk, until sauce thickens and becomes glossy.

Add fried chicken and blanched broccoli to the sauce. Toss with tongs for 1-2 minutes until everything is well coated.

Remove from heat. Serve immediately over hot rice, garnished with sliced green onions and sesame seeds. Remove dried chilies before eating or warn diners - they're very spicy.