Preheat Dry Air to 300c with 30% max humidity. Combine sliced Champignons with salt and half the olive oil and roast for 8 to 12 minutes, or untill the are browning nicely in spots. Take them out some time before thefirst mushrooms in the corner are starting to dry out
With the max humidity the actual temp will not reach higher then 230 or so. But do keep an eye out on anything burning.
Repeat with Oyster mushrooms but roast them less long.
Cook onions with some oil and half the salt in a covered pot for 10-20 minutes or untill translucent minutes on medium heat Add garlic and sweat for 1 Minute. Add Mushroompowder and pepper, thyme, majoram, MSG, and Soy sauce, stir, then deglace with white Wine and reduce for 5 minutes on medium high. Add in Cream and creme fraiche and a splash of water. Add the mushrooms in and simmer for a couple of minutes, untill the texture is just slightly runny, but thick.
Add the majoram and season to taste with salt, pepper and white Vinegar.
Serve with crusty bread, pasta or potatoes.