A rolled fillet of salmon is coated with sesame seeds before being grilled. To cook the salmon in the oven, heat the broiler and line a broiling pan with aluminum foil. Cook the fillets about four minutes per side.
Heat a grill or grill pan until hot. Place a salmon fillet on a clean work surface. Using a sharp knife, slice the fillet open horizontally, leaving one end intact. Spread fillet open, and turn over. Season with salt and pepper. Tightly roll the fillet. Secure with a wooden toothpick. Repeat with remaining fillets.
Pour sesame seeds into a small dish. Place a roulade in the seeds, and thoroughly coat bottom; drizzle sesame-coated side with olive oil. Repeat on other side. Coat and drizzle the remaining three roulades.
In a small bowl, whisk together vinegar and soy sauce; set aside.
Fold the edges of a piece of heavy-duty aluminum foil to form a shallow baking pan; place on grill. Arrange roulades on foil; grill until opaque halfway through, 4 to 6 minutes. Turn roulades over; grill until cooked through, 4 to 6 minutes. Remove from grill, and drizzle with reserved soy mixture. Serve on a bed of cucumber strips, if desired.