Over medium heat in dutch oven, heat peanut oil and brown spareribs in batches on all sides sprinkling with salt.
Return all spareribs to pan and add rice vinegar and garlic. Cover and cook until simmering over med/low heat for 45 minutes, stirring occasionally to coat the spareribs.
Add sugar and tamari sauce, return to a boil and reduce to simmer. Cook 30 minutes until meat is just tender, stirring occasionally to coat. Sauce will thicken slightly through reduction.
Turn off heat, keeping spareribs in dutch oven, allow them to cool for 1 to 2 hours to marinate.
Over medium heat, return to serving temperature and add pineapple and green pepper and cook for 15 minutes until pineapple is warmed through.
In a small bowl add cornstarch to 4 tablespoons of the reserved pineapple juice. Mix thoroughly to thicken sauce and add spareribs.
Serve over Asian rice.
