Put the walnuts in a cast iron skillet or other heavy skillet and toast over medium heat until you start to smell them and they begin to brown, stirring constantly. This will take about 10 minutes or so. Cool slightly and then give them a rough chop. Set aside.

Remove the sausage meat from the casing and brown over medium heat until there is no pink left. Set aside.

Cook the ziti according to package directions, to just shy of al dente. I usually cook my pasta a good 2 minutes short of what the package says.

Pluck the sage leaves off their stems and finely slice them. You should have at least 1/3 - 1/2 cup.

Melt the butter in a large skillet (big enough to hold the final dish) over a good medium high heat and add the sage. Let the sage sizzle and cook for two minutes, just until the butter begins to brown, Stir fairly constantly.

Lower the heat and add the cream, stirring to combine. Add salt and pepper, sausage, and walnuts to the pan.

When the pasta is just tender, drain and add it to the sauce, reserving a little of the cooking liquid.

Toss well with lemon juice, cheese, and parsley and heat through. Add a little more cream, or some of the reserved cooking liquid if the sauce seems skimpy. Taste and add salt, pepper, or more lemon juice.