Prep the aromatics: Halve the shallot. Keep garlic cloves whole. If you like extra heat, leave some chili seeds; for milder sauce, remove them.
Air fry to roast: Place shallot, garlic, chili, and peanuts on a small piece of foil or in a shallow air fryer-safe dish.
Lightly spray or toss with oil. Air fry at 375°F (190°C) for 6–8 minutes, shaking once, until the peanuts are fragrant and the aromatics are lightly charred at the edges.
Blend the base: Add roasted shallot, garlic, chili, and peanuts to a blender. Pour in coconut milk, peanut butter, soy sauce, fish sauce (if using), sugar, lime juice, vinegar, coriander, cumin, and turmeric.
Blend until smooth and creamy.
Adjust consistency: If the sauce is too thick, add warm water 1 tablespoon at a time until it’s pourable but still rich. Aim for a smooth, spoon-coating texture.
Taste and balance: Add more lime for brightness, sugar for sweetness, soy for saltiness, or chili for heat. Season with a pinch of salt if needed.
Warm (optional): For a silky finish, pour the blended sauce into a small heatproof dish and return to the air fryer at 300°F (150°C) for 2–3 minutes, stirring once.
This melds flavors without scorching.
Serve: Drizzle over skewers, grilled meats, tofu, noodles, or roasted vegetables. It’s also great as a dip with cucumbers or lettuce wraps.