Slice chicken into 1/2-inch strips, chop bell peppers, slice zucchini, thinly slice red onion, halve cherry tomatoes, mince garlic, chop parsley, and juice the lemon.

Heat 1 tablespoon olive oil in a large nonstick skillet over medium-high heat until shimmering.

Add chicken in a single layer. Season with salt, pepper, and half the oregano. Cook undisturbed for 3 minutes to get a good sear. Flip and cook for 2 more minutes until no longer pink. Remove chicken and set aside.

Reduce heat to medium. Add the remaining tablespoon of olive oil to the same pan. Add garlic and red onion. Cook for 1 to 2 minutes until fragrant and slightly softened.

Add bell peppers and zucchini. Stir occasionally and cook for 4 to 5 minutes until vegetables are tender but still have a bit of crunch. Add cherry tomatoes and cook for 1 more minute until they begin to soften.

Return the chicken to the pan. Sprinkle smoked paprika and the remaining oregano. Taste and adjust salt and pepper. Squeeze lemon juice over everything and stir to combine. Cook for 2 to 3 minutes until heated through.

Remove from heat, garnish with chopped parsley, stir gently, and serve immediately.