To make aioli, combine mayonnaise, basil, garlic, oil, lemon juice, 1/4 teaspoon each salt and pepper in food processor. Blend until a smooth puree. Turn into serving bowl. Stir in sun-dried tomato strips.
Sprinkle chicken with remaining 1/2 teaspoon salt and 1/4 teaspoon pepper.
Lightly coat large nonstick grill skillet with nonstick vegetable-oil cooking spray. Heat over medium-high heat. Working in batches if necessary to avoid crowding skillet, add chicken to skillet; cook 6 to 7 minutes per side until lightly browned (170°F).
Remove chicken to serving platter; pour any drippings over top. Serve with aioli, and orzo, if desired.