Place slices on a baking sheet. Brush or lightly drizzle both sides with 3 tbs olive oil, then season with 1 tsp kosher salt and 1/2 tsp freshly ground black pepper.

Bake until golden and crisp, about 8–10 minutes, flipping once halfway. Remove and let cool on a rack.

Steak

Pat the flank steak dry with paper towels. Rub both sides with 1 tbs olive oil, 1 tsp kosher salt, 1/2 tsp black pepper and 1/2 tsp garlic powder.

Preheat a grill or grill pan over high heat until very hot (around 450–500°F). Oil the grill grates lightly.

Grill the steak 4–6 minutes per side for medium-rare (internal temp 125–130°F), adjusting time for thickness and preferred doneness.

Transfer steak to a cutting board and tent loosely with foil. Let rest 8–10 minutes to retain juices.

Slice the steak thinly across the grain into bite-sized pieces that will fit on crostini (about 1/4-inch slices).

Caesar Spread

In a bowl, combine 1/2 cup mayonnaise, 1/4 cup plain Greek yogurt, 2 minced anchovy fillets, 1 minced garlic clove, 1 tsp Dijon mustard, 1 tbs fresh lemon juice and 1/2 tsp Worcestershire sauce.

Whisk in 1/4 cup grated Parmesan until smooth. Season with 1/4 tsp freshly ground black pepper and taste; add up to 1/4 tsp salt if needed.

If the spread is too thick, thin with 1–2 tsp water or additional lemon juice to a spreadable consistency.

Assembly & Garnish

Spread about 1 tablespoon of Caesar spread on each crostini (adjust to preference).

Top each crostini with a small handful (about 1 Tbsp) of thinly sliced romaine to add crunch and freshness.

Place 2–3 slices of grilled steak on each crostini (or one folded slice depending on size).

Finish with a few Parmesan shavings and a light sprinkle of lemon zest and chopped parsley if using.

Arrange on a platter and serve immediately so crostini remain crisp.