Heat the oil in a large non-stick wok/pan like this to keep everything moving easily. Add the sliced onion and cook for 3–4 minutes until softened. Stir in the garlic and ginger and cook for another minute until fragrant.
Add the Thai red curry paste and cook for 1–2 minutes to release the flavours.
Toss in the sliced peppers and stir to coat in the curry paste.
Pour in the coconut milk and stock, then stir in the fish sauce and sugar. Bring to a gentle simmer.
Let it cook for 5 minutes, until the peppers start to soften and the sauce thickens slightly.
Add the prawns and cook for 3–4 minutes, until they turn pink and are cooked through.
Squeeze over lime juice (a citrus squeezer like this makes it a breeze), taste, and adjust seasoning if needed. Ladle into bowls, this ladle makes it super easy to serve with plenty of sauce. Serve hot, scattered with fresh coriander, alongside jasmine rice or noodles.