Rub some oil on your palms and then rub each bell pepper with your palms to coat it slightly with oil. Don't worry about the oil-- the skin will come off, but the oil will help your peppers roast better.
Place the bell peppers on a baking sheet and roast in a preheated 500-degree oven for 30-40 minutes or until the skins are all black and wrinkly.
Remove the bell peppers form the oven and set aside to cool.
When they are cooled, remove the skins which will come off easily. Deseed the peppers and cut them into thin strips. Set aside.
Cook the pasta per package directions, in salted water.
While the pasta is cooking, heat the olive oil in a large saucepan.
Add the onions and garlic and saute, stirring frequently, until the onions are soft but not browned. Add some salt, red pepper flakes and the ground black pepper.
Add the leeks, sage and thyme and saute a few more minutes until the leeks are tender.
Add the pasta and stir well to mix.
Add the roasted bell peppers and parsley. Mix well and turn off the heat.
Add the lemon juice and more salt if needed. Serve hot or warm. If you don't mind the oil, drizzle in some extra virgin olive oil just before serving for extra deliciousness.