In a 6 to 8 quart, heavy bottomed casserole or Dutch oven, heat the olive oil over high heat until it is just smoking. Season the venison chunks with salt and pepper and sear the pieces on all sides until browned, turning with long-handled tongs. You may have to work in batches to avoid overcrowding the pan. Remove the browned meat to a plate and set aside.


To the same pan, add the onion, carrot, celery and garlic and, stirring constantly with a wooden spoon, cook them until lightly browned, 5 to 7 minutes. Add the tomato paste, stir through and cook until rusty red brown, about 7 minutes. Add the wine, beer, stock and rosemary and bring the mixture to a boil. Return the meat to the pot submerging it in the liquid and bring to a boil. Reduce the heat to a simmer and cook, uncovered, until the meat is tender and falling apart, about 1 ½ hours.


With a small ladle, skim the fat from the surface of the sauce and cool until reduced to the consistency of a very thick sauce. Adjust the seasoning with salt and pepper.
Bring 6 quarts of water to a boil and add 2 tablespoons of salt. Add the tagliatelle and cook in the boiling water until tender yet al dente, about 1 minute. Drain well.


Ladle 2 to 3 cups of the ragú into a 12 to 14 inch sauté pan, and stir for 1 minute over high heat. Add the pasta to the sauté pan with ragu. Toss gently over medium heat to coat the pasta with the ragú, 1 to 2 minutes. Divide among 6 heated plates and grate Asiago over each bowl. Serve immediately.