Step one: Freeze the plant after removing all the fan leaves.

Step two: Perform a bubble hash extraction (if using a machine use less ice or let the ice melt before turning it inand only add more slowly to about contamination, there's also polishing which is dropping the washed hash into distilled water and scooping out the stuff that floats ontop)

Step four: Freeze dry the following then mix

The bubble wash bags that collect the highest quality of hash are the 120, 90, 75, and 45 micron bags. When the hash collected from these bags is mixed together, that is called full spectrum bubble hash. 

Step five: Vacuum seal in a bag and allow to cure for a couple months.

The trick lies in allowing as little oxygen as possible to the product and letting the terpenes break down the components so they blend together. This whole thing is essentially a spin on Frenchy's temple ball Tek except the full melt nature of the product allows for a somewhat faster process.

This is all a bit of a hasty generalization and Duckduckgo has more info if you look up whole plant fresh frozen bubble hash but the general gist is simply: Take bubble hash from frozen plants, mix together all the best runs, then lend it meld together away from air.

It's tricky. It's involved. But it's far from magic.

(There's some posts that suggest you may be able to speed things up by giving the bag a brief sous vide bath before finishing up in the fridge but don't quote me on that)