Preheat your oven to 400 degrees
Place the diced pumpkin on a parchment lined baking sheet and drizzle with extra virgin olive oil and season with salt and black pepper
Roast the pumpkin for 20-25 minutes or until fork tender
While the pumpkin is roasting, place a skillet over medium heat and add the diced yellow onion
Cook the onion for 5-7 minutes or until softened
Once the onions have softened, add 4 cloves of garlic and cook, stirring consistently, for about 60 seconds
Add the ginger paste, serrano peppers, tomato paste, spices and plum tomatoes into the skillet with the onions and garlic and stir to combine
Add 1 cup of water and 1/4 cup of brown sugar and bring the mixture up to a simmer
Cook until the tomatoes begin to break down
Transfer everything into a blender or food processor and blend until smooth
Pour the mixture back into the skillet and reduce the heat to medium low
Add 1/2 cup of heavy cream and 2 tablespoons of butter into the curry
As soon as the pumpkin is fork tender, add it into the curry along with 1/4 cup of finely chopped fresh cilantro and toss to combine
Serve with rice and garnish with lime wedges