Blend brown sugar and curry powder in small saucepan. Gradually add soy sauce, tomato sauce and onion stirring until blended. Bring to boil, reduce heat and cook slowly for 5 minutes. Cool. Place steaks in large plastic bag. Add marinade. Press air out of bag and close tightly. Place in pan or dish. Marinate 4 to 6 hours or overnight in refrigerator.
Remove steaks and place on grill over hot, glowing coals. Broil steaks at low to moderate temperature basting and turning occasionally for 30 to 40 minutes.
