In a Mixing Bowl or zip-lock bag, whisk together the 3 tbsp olive oil extra-virgin, 2 tbsp fresh lemon juice from about 1 lemon, 3 cloves garlic minced, 1 tsp dried oregano, ½ tsp kosher salt, and ¼ tsp black pepper freshly ground. Add the 1 ½ lb boneless skinless chicken breasts pounded to even thickness, turning to coat evenly. Marinate for at least 15 minutes at room temperature, or up to 4 hours in the Fridge.

Preheat your Grill or Grill Pan to medium-high heat. Remove the 1 ½ lb boneless skinless chicken breasts pounded to even thickness from the marinade and shake off any excess. Grill for 6–7 minutes per side, until the internal temperature reaches 165°F and grill marks form. Transfer to a Cutting Board and let rest for 5 minutes before slicing diagonally.

Rinse peppers under cold water and pat dry. Slice off tops and bottoms, stand upright, and cut down along the inside to remove seeds and white ribs. Slice lengthwise into ½-inch strips; halve crosswise for shorter pieces. Keep sizes uniform so everything cooks evenly. If adding onion, slice it now. Measure out olive oil, salt, and pepper. Have everything ready before the pan goes on — sautéing moves fast.

Heat a large Skillet over medium heat. Add 1 tbsp olive oil per 2 peppers; warm 30–60 seconds until shimmering. Add pepper strips in a single layer — work in batches if crowded. Season with salt and pepper, stir to coat. Cook over medium heat, stirring every 2–3 minutes, for 6–10 minutes. At 6 minutes: slightly softened with snap. At 10 minutes: tender throughout with light color. For very soft peppers, cook 30–40 minutes over medium-low, stirring occasionally. Add garlic halfway through cooking. If browning too fast, add a splash of white wine or water and briefly cover to steam.

In a large Mixing Bowl, combine the sliced 1 large English cucumber halved lengthwise and sliced into half-moons, 2 cups cherry tomatoes halved, 0.5 whole red onion thinly sliced, and 1 whole green bell pepper seeded and chopped into bite-sized pieces. Drizzle the dressing over the vegetables and toss gently to coat.