Preheat a grill.

Drizzle the chicken with oil and season with salt, pepper, and Essence. Place on the grill and cook until cooked through, about 4 minutes on the first side, and 5 minutes on the second side. Remove the chicken from the grill and ;let cool briefly, then cut into bite-size pieces and set aside.

Bring a large pot of salted water to a boil. Add the pasta and cook until al dente. Drain the pasta, rinse with cool water and place in a large mixing bowl.

Toss the pasta with the Arugula Pesto, to taste. Stir in the chicken, tomatoes, feta, and olives and toss to combine, making sure that all of the ingredients are well-coated. Adjust the seasoning, to taste. Cover and chill in the refrigerator until ready to serve.  The pasta can be served cold, room temperature or warmed, with addtional olive oil drizzled over the top, if desired.

Arugula Pesto: In a food processor, combine the arugula, parsley, walnuts, garlic, cheese, lemon juice, salt, and pepper, and process on high speed until the greens are finely chopped. With the machine running, add the extra-virgin olive oil and 1/4 cup of the olive oil in a steady stream and process until smooth.