As above, Myprotein and I use unflavoured. 1 scoop protein, 2 scoops powdered porridge oats with 300ml water/skimmed milk mixture and it tastes superb. The unflavoured protein just tastes like creamy milk, I can’t handle the sweetness of the flavoured versions!
If you’ve not ordered from myprotein before use referral code MP24976472 and you should get a discount (10%?) on your first order (or if you have just sign up with a new email address)