For the 'cream' I've tried using soy milk with four and nutritional yeast mixed in but it has always either turned out sloppy and slimy from too much liquid or thick enough but with a distinct flour taste. Also, no matter what consistency I end up with, it's always wayyyy too sweet and just not appealing to the taste buds at all.
#1 pressure point: if you're using flour in nearly anything baked, you need to cook the rawness out of it first. Start by making a "roux" with Nuttlex and flour, you'll find recipes all over the net for this. Substitute butter with Nuttlex! Once the roux is done, chuck in your soy milk in incremental amounts. OR: use arrowroot to thicken the 'cream', forgetting about the flour altogether.
#2 pressure point: good move with the yeast, but the reason it's turning out too sweet could be maybe too much yeast, and not enough seasoning. Taste the 'cream' constantly while you're cooking it... add salt, pepper etc according to taste. Also try putting a little Tofutti cream cheese in there for some flavour and thicker consistency.
#3 pressure point: it sounds as if you are not par-cooking your spuds first. Not doing this can alter the flavour of the dish as the potato starches start doing their thing during cooking. This also adds more liquid while the dish is in the oven. If you're not par-boiling, cut 'em in half and throw them in boiling water for five minutes or so, and don't forget to drain them really well... if you are doing it, forget this step!
Also, I'd try putting some extra flavours in there. I really like my potato bake with some whole mustard seeds and a little cayenne pepper mixed throughout prior to baking. You only need a heaped teaspoon of mustard seeds for the whole dish to up the ante on the flavour. If you're using dry mustard seeds, don't forget to 'toast' them first, by putting them in a hot frying pan (no oil) for just a few seconds as you swish them around. If they smell burnt - they are burnt.
I hope this helps!
