Preheat the oven to 200°C and line a roasting pan with baking paper.
Mix the pumpkin, oil, garlic and rosemary together and season with sea salt and freshly ground pepper. Place in the roasting pan and roast for 35-40 minutes until golden and tender.
Meanwhile, for the pesto, place the parsley, almonds and garlic in a food processor and blend until well combined.
With the motor running, gradually add the oil in a slow, steady stream, until smooth, then season with sea salt and freshly ground pepper. Set aside.
Preheat a grill to medium.
Season salmon lightly with sea salt and freshly ground pepper. Wrap each salmon fillet with a slice of prosciutto. Brush lightly with oil and grill for 3-4 minutes each side until cooked on the outside but still a little pink in the centre. Rest, loosely covered with foil, for 2 minutes.
Divide the salmon and pumpkin among 4 serving plates and top with the parsley pesto.