Cook gemelli according to package directions.

Heat oil in a skillet set over medium heat, sauté pancetta for 2 to 3 minutes. Add onion; sauté until tender.

Add peas, water, red pepper flakes and parsley; continue cooking until peas are tender and heated through. Season to taste with salt and pepper.

Toss hot gemelli with pea mixture. Sprinkle with additional parsley, if desired.