Prepare backstrap. Rub meat with olive oil, and season with garlic powder, salt and pepper. Place on a white-hot-grill, and sear on both sides, but not past medium-rare, about 2 minutes per side. Remove from heat, and let rest at room temperature. When cooled, cut into 1-inch chunks.
In a large pot over medium heat, lightly brown bacon. Add onion, carrot, parsnip and garlic. Cook for 4 to 5 minutes. Add rosemary, stock, soy sauce and tomato paste. Bring to a boil, reduce heat to low and simmer for 15 minutes. Add mushrooms, and simmer until soft, but not limp and overcooked. Add venison, and cook for 2 minutes.
Remove rosemary sprigs, ladle soup into bowls and top with shredded cheese.
