Spaghettini with Garlic and Lemon

1 lb. Spaghettini
4 large garlic cloves
1/2 to 3/4 tsp. dried hot pepper flakes
1/2 c. olive oil
Finely grated zest from 2 lemons
3 Tbsp. fresh lemon juice (we like more)
1 1/2 tsp. salt
1/2 tsp. black pepper
1/2 c. chopped fresh flat-leaf parsley

Reserve 1 c. of boiling pasta water

Cook pasta
While pasta is cooking, cook garlic and red pepper flakes in oil over moderate heat until garlic is golden (be careful not to let the garlic get too brown). Add lemon zest and juice, salt pepper and 1/2 cup of reserved cooking water, bring to a simmer.
Toss in pasta, add parsley.

We like to add shrimp to this dish, marinate the shrimp in lemon juice and garlic, cook and add shrimp and juice to pasta.