Roasted Potatoes with garlic

1 1/2 lbs baking potatoes , peeled and quartered lengthwise 1 large sweet red pepper, halved,stemmed,seeded and cut into 8 wedges 1 large sweet green pepper,[...]

3 potatoes , sliced 1/4 inch thick 1 onion , peeled and sliced into 1/4 inch rings 5 garlic cloves , roughly chopped 3 tablespoons olive oil salt and pepper 1[...]