Preheat oven to 400°F
Toss peppers with 1 tbsp olive oil, 1/2 tsp salt, and 1/4 tsp pepper
Place on baking sheet and roast for 20 minutes until charred
Meanwhile, season chicken breasts with 1 tbsp olive oil, 1/2 tsp salt, and 1/4 tsp pepper
Grill or pan-sear until cooked through (4-5 minutes per side)
In a large bowl, combine mixed greens, roasted peppers, cucumber slices, and feta
In small bowl, whisk remaining olive oil, lemon juice, garlic, and pepper
Drizzle dressing over salad and toss to combine
Divide into 4 servings and garnish with additional feta if desired