Not-stuffed mushrooms

Although we quite like the idea of Stuffed mushrooms from Everyday Paleo, we knew that realistically it wasn't going to happen!  It had been suggested that you can just add all the mushrooms to the meat mixture to make burgers, and we have done this before.  But after the enthusiasm of the mushrooms with the pork burgers, I thought this may be worth trying.
So, I prepared the meat mixure as the recipe says (with the exception of the sausage), up to point of making burgers, when I made a giant 'tray bake' of meat mixture, as the mixture was not going to fit on one tray as burgers.  Then I chopped the mushroom tops with onion and fried them off as a topping.
Served with vegetables, it makes a filling meal.