You're Making Hot Chocolate Wrong, And It's Why It Tastes Thin And Grainy
The order you add things actually matters.
You dump the powder into a mug, pour hot milk over the top, stir like mad, and still end up with lumps floating on a thin, watery drink. A rich hot chocolate is not luck, it is technique.
Cocoa and chocolate do not dissolve happily when dropped straight into hot liquid. They clump. The trick is to make a smooth paste first with a small splash of liquid before you add the rest.
Warm your milk gently, whisk a little of it into the cocoa to form a paste, then stir that paste back into the pan. For real depth, melt in a few pieces of actual chocolate rather than powder alone.
A pinch of salt lifts the flavour and gentle heat keeps it silky, so never let it boil hard. Build it in the right order and you get a thick, glossy hot chocolate worth curling up with.