Garlic Lamb with Mushrooms

1 leg lamb, boned 
4 tomatoes, diced 
1 small can of champignon mushrooms 
2 small parsnips, chopped 
1/2 cup tomato paste 
1 clove garlic, minced 
4 teaspoons sugar 
1 teaspoon rosemary 
salt and pepper to taste 

Mix all ingredients except rosemary and stuff into the leg of lamb (where the bone was). 
Secure with skewers or toothpicks. 
Brush outside with olive oil and sprinkle rosemary over the leg. 
Place on preheated grill and cook indirectly for about 30 minutes per pound or 
until the meat is tender and juices from the thickest part of the leg run clear.