Heat the oil in a large saucepan over medium-high heat, until almost smoking. Brown the bison meat in the hot oil until golden brown, then remove from the pan to a plate and set aside.
In the same pan, add the onion, carrots, celery, garlic and saute for about 5 minutes, stirring constantly. Add the flour and tomato paste and stir well. Slowly add in the beef stock, red wine and canned tomatoes. Season with salt and pepper, to taste. Return the seared meat to the pan and reduce the heat to a simmer. Continue to cook for about 45 minutes. The liquid, when close to finishing, should have reduced in volume by 1/2 of what you started with and the meat should be fork tender. Cook's Note: if the liquid begins to evaporate you can add more stock or water.
To finish, stir in the fresh herbs and the butter. Transfer the stew to a serving bowl and serve immediately with wild rice or couscous.