Heat olive oil in a large skillet over medium heat. Add the thinly sliced onion and sauté for about 2–3 minutes until it begins to soften.
Add minced garlic, diced red bell pepper, and half-moon sliced zucchini to the skillet. Cook everything together for approximately 6–8 minutes, stirring occasionally until the vegetables are tender and lightly golden.
Stir in the halved cherry tomatoes, chopped sun-dried tomatoes, halved Kalamata olives, and capers if using. Allow this mixture to cook for another 3–4 minutes so that all the flavors meld together beautifully.
Season your skillet with dried oregano, smoked paprika, salt, black pepper, and chili flakes if desired. Briefly sauté to ensure that all spices are well incorporated into the vegetables.
Remove from heat and stir in lemon juice along with freshly chopped herbs like parsley or basil. If you like, garnish with crumbled feta before serving warm alongside couscous, quinoa, or crusty bread.