Wash and dry produce.

Halve, peel, and dice onion. Trim and halve zucchini lengthwise; slice crosswise into ½-inch-thick half-moons. Drain corn. Peel and mince garlic.

Heat a drizzle of olive oil in a large, preferably nonstick, pan over medium-high heat. Add onion and zucchini; season with salt and pepper. Cook, stirring occasionally, until browned and tender, 5-6 minutes.

Add corn and garlic; cook, stirring constantly, until fragrant, 30-60 seconds. Turn off heat.

Add romesco sauce and 1 TBSP butter (2 TBSP for 4 servings); stir to coat. Transfer to a large bowl and cover with foil. Wipe out pan.

Pat chicken* dry with paper towels and season all over with 1 tsp Italian Seasoning (2 tsp for 4 servings), salt, and pepper. (Be sure to measure the Italian Seasoning—we sent more!)

Heat a drizzle of oil in pan used for veggies over medium-high heat. Add chicken; cook until golden brown and cooked through, 5-7 minutes per side.

Transfer to a cutting board.

In a second large bowl, whisk together half the vinegar, 1 TBSP olive oil, and a pinch of salt and pepper (all the vinegar and 2 TBSP olive oil for 4 servings). Add mixed greens; toss to coat.

Slice chicken crosswise.

Divide corn and zucchini romesco and chicken between plates. Serve with salad on the side.