Now this may be the shortest post I may ever write, as this tasty and elegant side dish is about as simple as a recipe can get, short of boiling water.
Make a soffritto by sweating some finely chopped onion in olive oil until translucent. Add some prosciutto, cut across the grain into thin strips, and continue cooking just until the prosciutto has lost its 'raw' look. Then add peas—frozen peas will do nicely—and stir. Allow the peas to cook and absorb the flavors of the soffritto. If using frozen peas, this will take no longer than five minutes. Season to taste and serve!
NOTES: This is yet another one of those dishes where measurements don't much matter, but for a bag of frozen peas, a half onion and two slices of prosciutto should be enough to flavor the peas nicely. This is a dish where you need not use the finest San Daniele prosciutto.
If using fresh peas, the cooking time may be considerably longer, depending on how fresh the peas actually are. But don't overcook them or they will lose their sweetness.
Two fine variations are piselli al guanciale and piselli alla pancetta, which use guanciale or pancetta instead of the prosciutto. They are more 'down home' but every bit as delicious.