Process shallot, garlic and ginger in a food processor until finely chopped.
Heat oil in a large saucepan over medium-high heat, add ginger mixture and chillies, stir occasionally until fragrant (2 minutes).
Add spices, stir until fragrant, add coconut milk, curry leaf sprig, lemongrass, cinnamon, star anise and 100 ml water and simmer until well-flavoured (10-15 minutes).
Season to taste with palm sugar and sea salt, add prawns, broccolini and mushrooms and simmer until prawns are just cooked through and vegetables are just tender.
Serve hot with steamed rice, scattered with fried shallots, broccolini and lime wedges.