Since both feta and capers are salty, taste this salad before adding any salt.
Mince together:
      1/2 cup fresh parsley leaves
      2 tablespoons drained capers (optional)
      1 tablespoon fresh oregano leaves
      1 small fresh jalapeño pepper or other chili pepper, seeded if less heat is desired
      2 cloves garlic
Place in a serving bowl along with:
      1/3 cup extra-virgin olive oil
Stir in:
      5 to 6 ounces feta cheese, coarsely crumbled
      About 12 Kalamata olives, pitted and finely chopped
      Salt if needed and ground black pepper to taste
Cook in a large pot of boiling salted water until tender but firm:
      1 pound penne
Place in a colander:
      1/2 small red onion, cut into rings
Drain the pasta onto the onion in the colander and immediately add both to the feta mixture. Toss gently to coat and combine. Serve at room temperature.