- Place potatoes in large saucepan and cover with cold water; bring to a boil. Cook 15 min. or until just tender. Drain and toss potatoes with olive oil, garlic, thyme, rosemary and 1/2 tsp (2 mL) salt. Wrap mixture in double-thick foil packet. Seal tightly.
- Meanwhile, mix fennel seeds, mustard seeds, peppercorns and remaining salt. Rub all over steak. Let stand 10 min.
- Place potato packet on grill preheated to medium-high. Cook 15 min., turning over packet halfway through cooking, until potatoes are tender. Meanwhile, grill steak 5 to 7 min. per side or until meat reaches 145°F (63°C) on an instant-read thermometer for medium-rare, or to desired doneness. Rest steak 10 min. before slicing and serving with potatoes.
To coarsely crush spices use a mortar and pestle, or crush under small, heavy-bottom skillet or saucepan.