Preheat the oven to 220°C (430°F)

Prep the Veggies.
A – Peel and quarter the onion.
B – Cut the zucchini in half and then slice it into 1/2-inch slices.
C – Cut the peppers in half, remove the core and seeds, and then slice into 1-inch slices.
D – Slice the eggplant into 1/2-inch slices.

On two baking trays or baking sheets, add some parchment paper/baking paper and add half the veggies to each tray. Drizzle olive oil and season with salt and pepper.

Bake at 430°F (220°C) for about 35 minutes until veggies are roasted and a little charred.