Place the butter, flour and lime zest in a mixing bowl. Using finger tips, mix until crumbly. Spread on a baking tray and bake until golden brown.
Heat the olive oil over medium heat and sauté the prawns until they turn pink. Add the WORLDFOODS Cambodian Chilli Stir Fry Sauce and simmer for 1 minute.
Remove from heat and divide among 8 shot glasses. Top with the crumble and serve warm.