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.

Return the skillet to medium heat and add the remaining 1/2 tablespoon of Olive Oil. Once shimmering, pour in the egg mixture. Let the eggs set at the edges for about 20 seconds, then use a Spatula to gently push the cooked edges toward the center while tilting the pan so the uncooked egg flows to the edges. Continue until the eggs are just barely set on top but still look slightly glossy — about 1–2 minutes total.

Scatter the sautéed vegetables evenly over one half of the omelette, then sprinkle the Cheddar Cheese on top of the vegetables. Using the Spatula, fold the bare half of the omelette over the filled half. Slide onto a plate, garnish with fresh Chives / Parsley, and serve immediately.