Creating the delectable Spicy Dragon Chicken is easy if you follow these steps:

1. Marinate the Chicken: In a bowl, combine chicken pieces with salt, pepper, soy sauce, and cornflour. Let it sit for about 10 minutes.
2. Heat Oil: Heat vegetable oil in a large skillet or wok over medium-high heat.
3. Cook Chicken: Add the marinated chicken to the hot oil and stir-fry until golden brown and cooked through (about 5-7 minutes). Remove the chicken and set aside.
4. Sauté Aromatics: In the same pan, add a bit more oil if needed, and fry the minced garlic, grated ginger, dried red chilies, and onion until fragrant and soft.
5. Add Bell Pepper: Toss in the sliced bell pepper and stir-fry for 2-3 minutes until tender-crisp.
6. Mix Sauce: In a small bowl, mix the chili paste, sweet chili sauce, and vinegar; pour this mixture into the pan.
7. Combine Chicken: Return the cooked chicken to the pan and stir well to coat all the ingredients in the sauce.
8. Adjust Seasoning: Taste and adjust salt and chili based on your heat preference.
9. Garnish: Remove from heat and garnish with fresh chopped cilantro for an extra pop of flavor.
10. Serve Hot: Transfer to a serving plate or bowl while still hot.