Make Caramelized Onions(See recipe - takes 1 hour) up to 3 days ahead and store in refrigerator (Keeps up to 3 months in freezer).
If using frozen broth, take out of freezer the night or morning before, to defrost in the refrigerator.
PREP
Prepare ingredients and have ready in separate bowls (Takes 20-30 minutes): Chop prosciutto, grate cheese, cut fresh herbs according to group.
FINISH THE DISH & ENJOY
Put a large covered pot of generously salted water to boil.
Warm up the caramelized onions in a large saute pan over medium-low heat. Stir in the garlic, reduce the heat to low, and cook, stirring frequently, for 3 to 4 minutes. Add the chicken broth and simmer, stirring occasionally, until reduced by about half.
Stir in the cream and cook over medium heat until bubbling. Stir in the chopped prosciutto and herbs, and turn off the heat. (To keep the herbs exquisite, do not heat the herbs more than 3-5 minutes.)
Cook the pasta in the salted boiling water, stirring occasionally, according to the package instructions (fresh pasta should only take a few minutes).
When the pasta is ready,quickly turn the heat for the sauce back on medium, then transfer the pasta to the sauce with a pasta fork or tongs, and stir to coat the pasta. Add the grated Parmigiano and toss well. (If too liquidy, turn up the heat and cook a minute or two longer until reduced. If too dry, stir in a bit more cream.)Enjoy hot immediately, with more Parmigiano and freshly ground pepper at the table.
Notes
Fresh Herbs - Err on the side of too many herbs instead of too few. It's hard to add too much.
Storing - Store tightly covered in refrigerator for up to two days.
Rewarming - On the second day, the flavors of the herbs are much more subtle, so it pays to refresh them by adding newly chopped marjoram or oregano, and whatever other herbs you have left over. I recommend using a little broth, milk or even water to rewarm the sauce (heavy cream can overpower the other flavors), using as little as necessary, one tablespoon at a time.
Tools
flat bottomed wooden spoon
fine cheese grater
small food processor, or kitchen scissors, for the prosciutto