Try to take large mushrooms. Of course this will depend on the number of ground beef, 1 mushroom about 1 heaping teaspoon of stuffing. RUB the mushrooms, turn off the legs and clean a little pulp with a teaspoon. Spread out and add salt inside. P.S.: the legs and flesh can be frozen, or you can use it in the recipe "grilled Turkey cutlets with mushrooms" or for soup.
Mix minced meat with chopped onion and dill, season with pepper, salt, and beat off.
Fill the mushroom caps with minced meat, slightly compacting.
Fry on the grill pan or grill grill. First, "seal" the minced meat down, 3 minutes, the fire is above average.
Turn over, cover with foil, bring to readiness, 5 minutes, medium heat. If you cook on the grill, wrap the mushrooms in foil and hold on gray coals for 5-7 minutes.