Preheat the oven to 425°F (220°C).
Trim and cut the zucchini into rounds and break the cauliflower into small florets. Place them on a baking sheet.
Drizzle olive oil, sprinkle salt, pepper, and mixed herbs over the vegetables. Toss gently to coat evenly.
Roast the vegetables in the preheated oven for about 20-25 minutes, until they are tender and slightly crispy at the edges.
While the vegetables roast, season the chicken breast with salt, pepper, garlic (minced from the 2 cloves), lemon juice, and a pinch of mixed herbs.
Heat a non-stick skillet over medium-high heat and sear the chicken breast for about 5-6 minutes per side until fully cooked and golden.
Once both components are ready, plate the roasted vegetables alongside the sliced chicken, and drizzle any extra pan juices over the top.
Serve warm and enjoy a balanced meal with a crisp, fresh finish.