Gently fry the onion and garlic in the butter and oil until soft and translucent (slow gentle heat).
Add the Amaretto and flambe, then turn off the heat.
Add the cream and gently warm through, add a splash of water to loosen the sauce if too thick and put to one side.
In a separate pan, sear the prawns in a little olive oil until cooked through then turn off the heat, let cool for a minute before pouring in the sauce.
Warm through, add a tiny bit of lemon juice, season and taste. You want a balance of warmth and sweetness from the disaronno but balanced with the salt and just a touch of the lemon juice to offset the sweetness..
You may at this stage need to add some more water to loosen.
Garnish with a sprinkle of chives and flaked almonds.