Season chicken breasts with olive oil, paprika, garlic powder, salt, and pepper.
Grill or pan-sear chicken over medium-high heat for 5-6 minutes per side, until cooked through (internal temperature 165°F). Let rest 5 minutes, then slice thinly.
In a small bowl, mix Greek yogurt and lemon juice to make the sauce.
Slice rolls in half and lightly toast if desired.
Spread yogurt sauce on both halves of each roll.
Layer lettuce, sliced chicken, tomato, cucumber, and red onion on the bottom halves.
Close sandwiches with top halves and serve immediately.
Tips
For extra flavor, add sliced avocado or a sprinkle of feta cheese.
Make ahead: prep chicken and veggies separately, assemble just before serving.
Store leftover components in the fridge for up to 2 days.