Place venison between plastic wrap or in a zipper-lock bag, and pound lightly until very thin. Season with salt and pepper, and place in a large bowl. Place corn, peppers and onion in the bowl. Drizzle olive oil and red wine vinegar, and toss to coat all. While tossing, season with additional salt and pepper.
Place venison, corn, peppers, onion and tomatoes on a white-hot grill and grill on all sides of each. Remove venison when just cooked, and allow to cool before slicing into 1-inch thick strips.
Remove corn kernels from cob, dice peppers, tomatoes and onions, and place in a stock pot. Add chicken broth, garlic and oregano. Bring to a boil over medium-high heat, reduce heat to low, and simmer for 10 minutes. Add venison and parsley, and heat for 1 minute. Season to taste with salt and pepper.