Make the quick pickled salad: In a bowl, whisk vinegar, sugar, salt, and red pepper flakes. Add cucumber, red onion, and carrot.
Toss and set aside to pickle while you cook. Stir once or twice.
Season the lamb: Pat the lamb dry. Toss with 1 tbsp oil, 1 tsp salt, 1/2 tsp black pepper, and half of the spice mix (garam masala, cumin, coriander, turmeric, chili, cinnamon).
Preheat the air fryer: Set it to 390°F (200°C) for 3 minutes.
Lightly oil the basket to reduce sticking.
Air-fry the lamb: Spread lamb pieces in a single layer. Cook 8–10 minutes, shaking halfway, until browned with a little char on the edges. Work in batches if needed.
Transfer to a bowl and cover loosely.
Sauté aromatics (stovetop): In a medium saucepan, heat 1 tbsp oil over medium. Add onion with a pinch of salt. Cook 5–6 minutes until soft and lightly golden.
Add garlic and ginger; cook 1 minute until fragrant.
Build the sauce: Stir in tomato paste and the remaining spices. Cook 30–60 seconds to toast. Add coconut milk and stock, whisk smooth, and bring to a gentle simmer.
Sweeten and balance: Add 1 tsp honey or brown sugar.
Taste and add more if you prefer a sweeter profile. Adjust salt and heat as needed.
Add the lamb to the sauce: Tip the air-fried lamb (plus any juices) into the sauce. Simmer on low for 5–8 minutes to marry flavors.
The sauce should coat the lamb and thicken slightly.
Finish: Squeeze in a little lime for brightness. Stir in chopped cilantro. Taste and adjust seasoning one last time.
Serve: Drain the pickled salad lightly.
Spoon curry over rice or with flatbreads. Top with more cilantro and a side of the salad. Add lime wedges for extra zing.