Dice onions and sauté with bacon and bacon fat until onions are soft and translucent.
Add venison to brown on all sides. Stir in tomatoes and seasonings.
Stir in broth and water.
Add the barley and stir.
Cover and simmer over medium low for at least an hour, until barley is tender.
Notes
I like 2 cups of tomatoes in my soup, but this is of course very forgiving. You can use home canned, or a small or large can from the store. A small can at the store is just under 2 cups, technically.
Use any type of broth. The tomatoes and bacon add a lot of flavour so even chicken broth is just fine.