Heat the cumin, coriander, fennel and cloves in a dry skillet over medium heat. Toasting spices before grinding them makes them smell good and taste better. Add turmeric, black pepper, cayenne and nutmeg.
In a bowl, place butter. Add spices, garlic, ginger, salt and lime zest and juice. Mash the spices into the butter, using a spatula.
Once it has come together, add almonds and scallions, crushed and chopped. Whisk until the ingredients are incorporated.
Put a heavy-duty pan on the medium-high fire. Add 3 tbsp of curry butter, let melt and swirl the pan to spread the flavour throughout.
Dust the crabs with rice flour. When butter is melted, add the crabs in a layer and turn up the heat.
Cook crabs for 3 minutes, then turn them around and cook a further 3 minutes.
Remove crabs from the pan and keep warm.
Put 4 tbsp curry butter in a pan and let it sizzle. Add pea shoots and cook for 1 minute or less until wilted.
Serving Suggestions: Set crabs on a warm platter or individual dishes. Top with a wilted handful of pea shoots and trim with lime wedges. Spoon the remaining curry butter from the pan over crabs and serve at once.