If chicken breasts are thick, butterfly or lightly pound to an even thickness (~3/4 inch). Pat dry with paper towel. Rub with 1 tbsp olive oil, garlic powder, lemon zest, 1/2 tsp salt and 1/4 tsp pepper.

Grill or pan-sear

Heat a grill pan or skillet over medium-high heat until hot. Add the chicken and cook 4–5 minutes per side (depending on thickness) until internal temperature reaches 165°F (74°C) and juices run clear. Remove from heat, let rest 5 minutes, then slice thinly across the grain into strips.

Make the creamy Caesar dressing

In a bowl, whisk together 1/2 cup mayonnaise, 1/4 cup Greek yogurt, 1/4 cup grated Parmesan, 1 tbsp lemon juice, 1/2 tsp Dijon, 1/2 tsp Worcestershire, 1/2 tsp anchovy paste (if using), 1 minced garlic clove, 1/4 tsp black pepper and 1/8 tsp salt until smooth. Taste and adjust seasoning or lemon for brightness. If the dressing is too thick, thin with 1–2 tsp water or extra lemon juice.

Prepare flatbreads

Preheat oven to 425°F (220°C) with a rack in the middle, or heat a large skillet over medium heat if you prefer stovetop crisping.

Brush both sides of each flatbread lightly with the 2 tbs olive oil and sprinkle with 1/2 tsp salt and 1/4 tsp pepper (split between breads). Place flatbreads on a baking sheet and bake 6–8 minutes until edges are crisp and lightly golden. Alternatively, cook in a preheated skillet 2–3 minutes per side until crisp.

Assemble flatbreads

Remove hot flatbreads from oven or skillet. While still warm, spread about 2–3 tbs of the creamy Caesar dressing evenly over each flatbread (reserve remaining dressing for topping).

Lay sliced grilled chicken evenly over the dressed flatbreads (about half the chicken per flatbread).

Top with chopped romaine (divide 1.5 cups per flatbread), shaved Parmesan (approx 2 tbsp per flatbread), and optional crouton pieces for crunch. Drizzle or dollop remaining dressing over the top to taste.

Finish with a squeeze of lemon, a light sprinkle of cracked black pepper, and a few extra Parmesan shavings.

Serve

Cut each flatbread into 6 slices (or as desired) and serve immediately while flatbread is warm and lettuce is crisp. Offer extra dressing and lemon wedges on the side.