This eclectic stir-fry is a colorful combination of carrot, red bell pepper, corn and romaine lettuce. This recipe exemplifies how to stir-fry vegetables with different textures. The carrots, which are a “hard vegetable,” should be stir-fried for a minute before adding “medium-hard” vegetables like peppers or corn, which require slightly less cooking. Finally, add “soft or leafy vegetables” in the last 30 seconds to ensure all the vegetables achieve the same level of doneness. Make sure the lettuce is dry--if it's wet when added to the pan, it will turn the stir-fry into a braise.