Giant Burger Stuffed with Mushrooms

Total time: 35 minutes       longer if using oven 
    You could make smaller burgers, but we like this big one.  Cut into wedges, with cheese oozing out of the center.... This one is filled with mushrooms, olives and Gruyère.

 Ingredients:

• 12oz (360gr) ground beef (mince)
• 2 slice prosciutto
• 1 - 2oz (30 - 60gr) mushrooms
• 10 black, olives, Greek or Kalamata
• 1oz (30gr) Gruyère
• 1 tsp olive oil
• If cooking on the barbecue: wire grill-basket or a mesh grill pan
• If cooking in the oven: baking sheet

 Instructions:

• Trim and chop mushrooms. 
• Chop olives. 
• Cut Prosciutto into thin strips. 
• Oil grill basket, mesh pan or baking sheet.
• Divide beef in half.  On plates or waxed paper pat each half into a thin patty, 8 or 9 inches (20 - 23cm) in diameter.
• Spread mushrooms, olives and Prosciutto over 1 patty to within 1/2 inch of edge. 
• Lay cheese on top.
• Flatten the second patty a bit more and carefully put it on top and work the edges together with your fingers to seal. Slide or tip it on to the grill basket and close basket.  If you don't use a basket you'll need a plate or baking sheet to help turn it.
• If using the barbecue, grill for 8 - 10 minutes over medium-high heat, carefully turn and grill another 8 - 10 or until done. 
• If using oven, bake at 400F for 35 - 40 minutes or until done. 
• Hint: When cheese starts oozing out of the edge I consider it done.
• Remove to platter, cut into wedges and serve.