Clean and slice the mushrooms. Heat 20 g fat in a large pan and add the steaklets without defrosting. Fry over medium heat for about 10 minutes. Turn several times and add the mushrooms halfway through the frying time.
In the meantime, wash and drain the tomatoes and chives. Cut the tomatoes into slices. Drain mozzarella and cut into slices as well. Put the pasta in boiling salted water and cook for about 7 minutes.
Season mushrooms with salt and pepper. Cover steaklets with tomatoes, spread half of the mushrooms on top and cover with slices of mozzarella. Season with salt and pepper, pour cream and broth over the remaining mushrooms, bring to the boil and simmer covered for about 2 minutes until the mozzarella has melted a little.
Add chives, except for a few stalks for garnishing, to the boiling pasta and cook for 1/2 minutes. Pour onto a sieve, rinse briefly under cold water and drain. Melt the rest of the fat in a pot and toss the chive noodles in it.
Arrange the steaklets on plates and garnish with red berries/pepper and chives.