Add ribs to pressure cooker and water. Cover with the lid and cook (following pressure cooker manufacturers instructions) for 45 minutes. Allow to cool slightly before releasing valve. Drain the ribs from any liquid in the pot.
In a large pan on medium/high heat, add the oil and fry the ribs till they are nicely browned. Set them aside.
In a small saucepan, combine all the ingredients to make the teriyaki sauce, and bring to a boil over medium-high heat. Reduce to simmer and cook till it is thick enough to coat a spoon.
Transfer the ribs to a large saucepan. Add the teriyaki sauce and sauté till the ribs are well coated in the sauce.