Add all ingredients into a food processor: Thai red chilies, red bell pepper, onion, lemon zest and juice, white vinegar, olive oil, garlic, smoked paprika, dried oregano, and salt. Blend for 30-60 seconds until chunky.

Taste and adjust heat if necessary by adding more Thai chilies and blending again.

Transfer the sauce into a clean jar or airtight container. Refrigerate for at least 30 minutes to enhance flavors.

To use, coat chicken legs with the sauce, ensuring even coverage. Marinate for at least 4 hours in the refrigerator.

For air fryer: Preheat to 400°F (204°C). Cook marinated chicken for 15-18 minutes, then flip and cook for an additional 5-8 minutes until internal temperature reaches 165°F (74°C).

For oven: Preheat to 425°F (218°C). Roast chicken on parchment-lined baking sheet for 30-40 minutes, reaching 165°F.