Preheat oven to 200℃.
Prick the potatoes with a fork and place on tray lined with rock salt. Bake for 1 hour or until the skin is crisp and the potato is cooked through.
Place the butter, green onion, garlic, jalapeño peppers, coriander, lime juice and zest into a bowl and mix until well combined.
Split the potatoes down the centre and top with prawns spoon over the butter and return to the oven for 2-3 minutes to warm through.
Top with crème fraîche, chilli and baby coriander leaves.