Preheat the oven to 120 degrees Celsius (248 degrees Fahrenheit) (fan).
Remove the stems from the mushrooms.
Place the mushrooms and cherry tomatoes on the vine on a baking sheet.
Drizzle a little olive oil over them and put a teaspoon of butter in each mushroom.
Sprinkle with Aromat seasoning and place fresh rosemary on top.
Put the baking sheet in the preheated oven and bake for 2-3 hours, depending on how much bite you want in the mushrooms and cherry tomatoes.
Once the cherry tomatoes are baked, they can easily be removed from the vine.
Spread the arugula on a platter and place the oven-baked mushrooms and tomatoes on top. Leave the juices in the mushrooms.
Pour some of the juices/oil from the baking sheet over the salad.
Crumble the feta cheese over the salad and sprinkle with a little fresh chopped rosemary.
Your superbly delicious mushroom salad is now ready to be served. Enjoy!