chicken and sage and onions and stuff

This was really tasty:

3 frozen chicken tenders, mostly defrosted, sliced into small pieces
marinated in:
juice of half a lemon
soy sauce
ground sage

then,
most of an onion, sliced
one carrot, sliced
maybe 5 mushrooms (which had been frozen, just thrown loosely into a plastic container and left for 3-4 months!), sliced
one small potato, microwaved to pre-cook it, sliced
and the chicken,
sauteed in some oil with some added paprika, with a lid on the pan

I added a bit of water at one point after the natural juices seemed to be drying up.
At the end I added this roux-ish thing I made out of a TBS of butter and some flour, which was a bit...odd, since I don't really know my way around roux.

But damn, the whole thing was super tasty. I think sage is my new favorite herb. And next time I'd like to try it without the roux. I'm curious how much the butter added. I hope it'd be tasty without it.
ETA: I made it again and it was fine without the butter mixture. I added an extra potato, also pre-cooked, which broke apart a bit and added some thickness. It doesn't look glamorous, but it's gooooood.