Heat oil in a Dutch oven over medium-high heat. Add onion and garlic to pan; sauté 5 minutes or until tender. Add buffalo; cook 5 minutes or until browned, stirring to crumble. Stir in chile powder and pepper.
Add 3 1/2 cups water, potato, and next 5 ingredients (through sage) to pan; bring to a boil. Reduce heat, and simmer 50 minutes or until potato is very tender. Stir in cornmeal; cook 5 minutes, stirring occasionally.