Rinse the mushrooms with cold water, dry, remove the legs and sprinkle with lemon juice.
Finely chop the mushroom stems. Peel and crush the garlic with a garlic press. Rinse greens, dry and finely chop.
Melt the butter in a frying pan, add garlic and mushroom legs, fry for 1.5-2 minutes. Then add greens and simmer for 1 more minute. Season the finished mixture with salt, pepper and stuff the mushroom caps with it.
In a bowl, mix flour, starch, a pinch of salt and paprika each, add the yolks, beer and knead the batter. Beat egg whites until stiff peaks form, add to batter and mix gently.
Heat oil in a saucepan. Dip the mushrooms in the batter and fry. Set the mushrooms aside in a colander to remove excess oil. Serve with French toast.