How to Make It
In a large pot, heat 2 tablespoons of the olive oil until shimmering. Add the venison, season with salt and pepper and cook over moderately high heat, stirring occasionally, until browned, 5 to 7 minutes. Transfer the venison to a colander set over a bowl and let drain.
Heat the remaining 2 tablespoons of olive oil in the pot. Add the onion and garlic and cook over moderate heat, stirring occasionally, until softened, 7 to 8 minutes. Stir in the carrots and celery and season with salt and pepper. Cook for 5 minutes, then add the wine. Simmer until reduced by half, about 3 minutes. Add the tomatoes, bay leaf, oregano and the drained venison and bring to a simmer. Cover and cook over moderately low heat, stirring occasionally and breaking up the tomatoes, until the venison is very tender and the sauce has thickened, about 1 1/2 hours. Discard the bay leaf and oregano sprigs.
Bring a large pot of salted water to a boil. Add the pasta and cook until al dente. Drain, reserving 2 cups of the cooking water. Add the pasta and 1 cup of the cooking water to the Bolognese sauce and simmer over moderate heat, tossing, until the pasta is nicely coated. Add more pasta cooking water if the sauce seems too thick. Remove the pot from the heat and stir in the cheese and butter. Season with salt and serve immediately.
Ground venison is available at specialty butchers and localharvest.org. Alternatively, you can substitute ground lamb for the venison.