1. Combine Worcestershire sauce, 1 tbsp (15 mL) of the oil, chives, mustard, horseradish (if using) and ¼ tsp (1 mL) pepper in a sealable freezer bag. Pierce steak all over with a fork. Add to bag, turning to coat; seal and refrigerate for at least 2 hours or for up to 8 hours.

2. Discard marinade from meat. Pat steak dry with paper towel. Grill in a closed preheated barbecue over medium-high heat (400°F) for 10 to 12 minutes, turning twice or more, or until a digital instant-read thermometer inserted sideways into centre of steak reads 145°F (63°C) for medium-rare at the least. Transfer to a cutting board and let rest.

3. Brush onion halves all over with remaining oil and place in grill basket. Grill in closed preheated barbecue over medium-high heat (400°F), turning occasionally, for about 10 minutes or until lightly charred all over.

4. Meanwhile, bake or grill the Furlani garlic Texas toast according to package directions. Transfer to a rimmed baking sheet and immediately top each toast slice with a slice of cheese. Return to heat just to melt the cheese. Spread with mayo/mustard/horseradish to your taste (if using).

5. On a large cutting board, slice the onion lengthwise into thin wedges and carve the steak across the grain into thin 2-inch (5 cm) long slices (like shaved roast beef); season steak and onion all over with salt and pepper to taste. Divide onion and steak slices equally among four toast slices on top of the cheese. Top each with remaining toast with melted cheese on fillings to make 4 sandwiches. Serve each sandwich with a knife and fork.

Tip

To make your own croutons to top soups or salads, cut Furlani garlic Texas toast into ½-inch (1 cm) cubes. Bake in preheated 325°F oven in a single layer on parchment-lined rimmed baking sheet, stirring twice or more, for 18 to 20 minutes, or until golden brown and crispy all the way through. Cool for 2 to 4 hours after removing from oven.