In glass baking dish, combine oils, peppercorns, rind, bay leaves, thyme, rosemary. Place fish in single layer in marinade; turn to coat. Cover; refrigerate at least 2 hours.
Prepare outdoor grill with hot coals or heat gas grill to high.
While grill is heating, in large shallow saucepan (fish should be submerged in single layer), combine oils and garlic. Heat oil until it registers 130°F to 150°F on deep-fat frying thermometer.
Remove swordfish from marinade, letting excess oil drip back into dish. Season fish with salt and pepper.
Grill swordfish in 2 directions to make crisscross pattern on surface, 3 minutes per side. Remove from grill.
Submerge steaks in single layer in oil; poach until cooked through, 10 minutes (do not boil).
To save oil for making recipe again, strain through cheese cloth; discard garlic. Refrigerate oil 3 weeks.