Bring 6 quarts water to boil and add 2 tablespoons salt.

In a 12 to 14-inch saute pan, heat the oil over high heat. Add the shallots and saute until light golden brown, about 5 to 6 minutes. Add the radicchio and cook for 30 seconds. Add the cream, reduce by half, and remove from the heat.

Drop the pasta into the boiling water and cook until tender yet al dente, about 2 minutes. Drain the pasta well and toss into pan with cream mixture. Return to heat, add lemon zest and juice, and toss over high heat to coat. Add half the cheese and toss again. Season with salt and pepper and serve immediately in a warm bowl, making the remaining Asiago available on the side.

Mound 3 1/2 cups of the flour in the center of a large wooden cutting board. Make a well in the middle of the flour and add the eggs and the olive oil. Using a fork, beat together the eggs and oil, and begin to incorporate the flour, starting with the inner rim of the well.

As you expand the well, keep pushing the flour up from the base of the mound to retain the well shape. The dough will come together when half of the flour is incorporated.

Start kneading the dough with both hands, using the palms of your hands. Once you have a cohesive mass, remove the dough from the board and scrape up and discard any leftover bits. Lightly reflour the board and continue kneading for 6 more minutes. The dough should be elastic and a little sticky. Wrap the dough in plastic and allow to rest for 30 minutes at room temperature.

Roll the pasta out to the thinnest setting on a pasta rolling machine and cut the sheets into 1/4-inch thick ribbons.

In a medium bowl, combine the eggs and spinach and stir well.

Mound 3 1/2 cups of the flour in the center of a large wooden cutting board. Make a well in the middle of the flour and add the egg and spinach mixture and the olive oil. Using a fork, beat them together and begin to incorporate the flour, starting with the inner rim of the well.

As you expand the well, keep pushing the flour up from the base of the mound to retain the well shape. The dough will come together when half of the flour is incorporated.

Start kneading the dough with both hands, using the palms of your hands. Once you have a cohesive mass, remove the dough from the board and scrape up and discard any leftover bits. Lightly reflour the board and continue kneading for 6 more minutes. The dough should be elastic and a little sticky. Wrap the dough in plastic and allow to rest for 30 minutes at room temperature.

Roll the pasta out to the thinnest setting on a pasta rolling machine and cut the sheets into 1/4-inch thick ribbons.