Cook the pasta in salted water according to the package instructions.
In a small pan, add the olive oil, garlic and red pepper flakes. Set the heat to low and cook until the garlic begins to sizzle, about 3 minutes. Remove from heat before garlic browns. Whisk in lemon juice, along with salt and pepper to taste.
Drain pasta and rinse with cold water. Place drained pasta in a large bowl along with peas and feta.
Toss with dressing and refrigerate until chilled. May also be served hot or at room temperature.