Fill a 500g mold/tin with water and empty it, leaving it moist with water. Do not dry it. Keep aside.

Whisk all the ingredients together in a heavy bottom pan.

Simmer over low heat for 8-10 minutes, whisking constantly, until it begins to thicken like a custard. Don't let it thicken too much, the consistency should be mayonnaise like.

Take off heat , whisk well, strain if desired and immediately pour into the prepared mold. Tap to remove bubbles if any. Cool for 30 minutes on the counter, then refrigerate for 6-8 hours, better overnight. Cover about 2 hours after the mold has been in the fridge so you don't trap the condensation.

To demold, place a platter over the top and firmly but gently turn over. You will hear the pudding gently plop onto the platter.

Garnish with rose petals and pistachio slivers.