1. In a covered 5- to 6-quart pan over high heat, bring 2 to 3 quarts water to a boil. Add macaroni and cook, uncovered, until barely tender to bite, about 6 minutes.
2. When macaroni is almost tender, add arugula; stir and cook just until leaves wilt, about 1 minute. Drain pasta and greens and put in a bowl. Quickly rinse and dry pan.
3. Add oil and garlic to pan over medium heat; stir until garlic is limp, about 1 minute. Add anchovies, olives, pepper, and chili flakes; stir and add pasta, greens, and 1/2 cup cheese. Mix well and pour back into bowl. Add more parmesan cheese to taste.