Whisk together all of the marinade ingredients (Oive oil, lemon juice, fennel, oregano, salt, pepper) in a medium bowl. Add the chickpeas and set aside. Bring a large, covered pot of water to a boil.

Meanwhile, warm the 1 tablespoon olive oil in a nonreactive saucepan and gently saute the garlic until just golden, a minute or two. Add the celery, bell peppers, and tomatoes and continue to cook, stirring occasionally, for about 10 minutes. Stir in the scallions and marinated chickpeas and cook for about 3 minutes.

When the water boils, cook the pasta until al dente. Drain in a colander, rinse under cool water, and drain again. Transfer the pasta to a large serving bowl and add the sauteed vegetables and the olives, parsley, and lemon juice. Toss well.

Serve warm or chilled, topping each serving with feta cheese.