Slow Roasted Baby Back Ribs

1 tablespoon dried parsley
1 tablespoon dried thyme
1 tablespoon dried oregano
1 tablespoon dried paprika
1 tablespoon garlic salt
1 tablespoon onion salt
1 tablespoon sugar
1 teaspoon freshly ground black pepper
2 slabs baby back pork ribs (about 4 pounds total)
1 to 2 cups barbecue sauce
Adjust the oven rack to the center position and preheat the oven to 225F. Lightly oil 2 rimmed baking sheets.
To make the Spice Rub: Combine the parsley, thyme, oregano, paprika, garlic salt, onion salt, sugar, and pepper in a small bowl.
To cook the ribs: If necessary, cut the rib slabs in half so that they can be arranged to fit on the baking sheets. Pat the spice rub onto the slabs, coating them allover as thoroughly as possible. Put the slabs on the baking sheets and roast them for 2 1/2 hours, turning them over twice during cooking. Remove the ribs from the oven and baste both sides of each slab with the barbecue sauce. Return to the oven and roast until the sauce is glazed, and just beginning to brown, about 15 minutes. Slice the slabs into individual ribs and serve warm.