This is whatni do and it works great. I do it for all HS meals.
Use the provided Huel pot
Boil water and add it to 1" above line
Stir, the fluid will go lower
Add more.boiling water to 1" above the line
Screw on cover
Wait 15 min
I pour my Huel HS over microwaved frozen vegetables. Mostly Organic Broccoli 
Also drink lots of water with it and a hot cup of tea as well.
Fancy a dessert, I have a glass of Huel Protein snack shake over Ice instead of tea.
Life is 