Ooooh, I think I would use the spinach, mushrooms, peppers and creme fraiche to make a pasta sauce.
If you fried the mushrooms and peppers off in frylight (along with an onion and maybe a clove of garlic?), then once softened, added the creme fraiche, a stock cube, seasoning/dried herbs and a dash of lemon juice, I reckon it would be cracking. You could then stir through some cooked pasta, and finally, before serving, stir through the spinach so that it is a little wilted.
I do a similar thing, but with chicken as well, and rocket instead of the spinach - it's one of my bf's favourites, and great for me on EE when served with a side salad.