In a large resealable bag, add steak along with cornstarch. Shake to coat steak well.
To a slow cooker add oil, garlic, soy sauce, water, brown sugar and carrots. Stir to combine.
Add steak and stir again to coat steak with sauce. Cook on high for 2-3 hours or on low for 4-5 hours, stirring once. Note: Both cooking times work, but I found that cooking 3 hours on high was perfect. Serve over steamed rice with a sprinkle of sliced green onion.