In a medium saucepan, cook onion, garlic, cumin, and crushed red pepper in hot oil about 5 minutes or until onion is tender. Stir in the 2 cups chopped tomatoes, half of the garbanzo beans, the salt, and black pepper. Cover and cook over medium heat until mixture is boiling; reduce heat. Simmer, covered, for 5 minutes, stirring occasionally. Remove from heat.
Carefully transfer the tomato mixture to a blender or food processor. Cover and blend or process until smooth. Return all to saucepan. Stir in the remaining garbanzo beans. Cook and stir over low heat until sauce is heated through.
Meanwhile, cook pasta according to package directions. Drain pasta. To serve, toss cooked pasta with sauce. Divide mixture between two serving plates. Top with the 1/3 cup chopped tomato and the feta cheese. Sprinkle with freshly ground black pepper. If desired, garnish with rosemary sprigs.