Depending on your guests, you can make either the tiny or the biggie variations of these hearty but glorious appetizers. To save time, you can buy rare roast beef at the deli counter.
- Portion size 32 servings
Trim crusts from bread; using rolling pin, roll each slice until about 1/8 inch (3 mm) thick. Cut each piece into quarters; brush lightly with vegetable oil. Tuck into 1-1/2 inch (4 cm) tart tins to form shells; bake in 350ºF (180ºC) oven for 10 to 15 minutes or until crisp and light golden brown. Let cool on racks. (Make-ahead: place in airtight container; store at room temperature for up to 1 week or freeze for up to 3 weeks).
In large shallow dish, whisk together vinegar, olive oil, minced garlic and pepper. Add steak, turning to coat. Let stand at room temperature for 30 minutes.
Broil or grill steak for about 7 minutes or until rare, turning once; let cool. (Make ahead: Place in covered container; refrigerate for up to 12 hours).
Slice grilled sirloin very thinly; cut each slice in half. Stir together mayonnaise and horseradish; spoon 1/2 tsp (2 mL) into bottom of each cup. Top with slice of beef. Sprinkle about 1 tsp (5 mL) Stilton cheese on top.