How to use these Mushrooms in food ?

They would be very good sauteed with butter and served with some scrambled eggs.  

You could make a quiche. 

I think they would make a very tasty Risotto or a baked Polenta. Saute the mushrooms with some rosemary and serve over the polenta that you stir some grated fontina cheese into. 

Personally I would go for the Quiche or the Risotto

All of those are good choices. If making pizza from scratch, they're good for that as well.

Those are oyster mushrooms.

I would want to use them in a way that their flavor can really shine, because it’s about breakfast time I’m thinking omelette.

I’d saute them in a little butter til barely cooked, then enfold them in a delicate omelette or crepe.

as they are ot fry them or boil them and mix it

Oyster mushrooms - use them like any other mushroom.

Sauteed in butter and tiny bit of garlic on a steak

https://www.thekitchn.com/best-mushroom-recipes-25...

i love em in homemade spagetti

https://www.mrfood.com/Editors-Picks/28-Mouthwater...

Like the other user said, fry 'em in butter and put them on a nice rare steak!

In an omelet, I'd slice them up and sautee them in some butter first until tender. In a salad, they would be fine just chopped up. If you need to store some it is best to place them in an airtight container of some sort with some paper towels in the bottom to absorb any excess moisture then place them in your refrigerator. They should remain usable for several days then.

Well, you could put them in a stew or you could saute them and serve them on a steak.