Sweat the onions & garlic in a deep casserole dish with the oil & butter until soft & translucent. Fry the diced beef in a heavy based frying pan over a high heat until rich & golden. Add curry paste, chilli (if using) & tomato to the onions & cook out for 5 minutes. Add stock, coconut milk & ½ the lime juice then bring to a simmer Thicken by whisking the corn flour mix into the simmering sauce Add beef to pot, cover & cook for 1½ hour in a preheated oven 130 oc Next add the pumpkin & peppers, place back in oven covered for 1 more hour until both beef & vegetables are tender. Carefully remove from oven, add an extra squeeze of lime, salt to taste then tear the basil leaves into the curry just before serving. Garnish with toasted pumpkin seeds. Serve with lots of basmati rice. Optional: Serve the curry in baked baby pumpkins