Heat vegetable oil in frying pan.
Coat sirloin steak with cornstarch. Place into hot frying pan and fry slices on both sides until done. Approximately 1-2 minutes per side. Remove from pan.
Add broccolini and cook until tender.
Make sauce by combining soy sauce, water, garlic, salt and pepper. Add mixture to frying pan.
Add steak and broccolini to pan and toss until tender and warm.
Remove steak and broccolini and serve atop a bed of rice. Enjoy!