Preheat your oven to 400°F (200°C).
On a large sheet pan, spread out the bell pepper, zucchini, and red onion.
Drizzle the vegetables with 1 tablespoon of olive oil and sprinkle with half the minced garlic, salt, and pepper. Toss to coat evenly.
In a separate bowl, toss the mixed seafood with the remaining olive oil, garlic, rosemary, thyme, salt, and pepper.
Arrange the seafood evenly over the vegetables on the sheet pan.
Place lemon slices around the seafood and vegetables.
Bake in the preheated oven for about 15-20 minutes, or until the seafood is cooked through and the vegetables are tender and slightly caramelized.
Serve immediately, garnished with additional fresh herbs if desired.