Cut chicken into 1-inch cubes; place in large bowl with pineapple and red onion cubes.
In medium mixing bowl, whisk together soy sauce, brown sugar, salt, lemon juice, ginger, garlic and oil. Pour mixture over chicken and pineapple. Cover with plastic wrap and marinate at least 1 hour in refrigerator, stirring twice.
Remove from refrigerator and thread chicken, pineapple and onion on metal skewers. (Use wooden skewers soaked in water for 30 minutes, if desired.)
Prepare grill to medium-high heat. Grill skewers over direct heat for 5 minutes per side, or until done. Baste with marinade each time you turn skewers.
*Use sirloin or tenderloin steak instead of chicken, if desired.