Preheat your oven to 425°F and line a large rimmed sheet pan with parchment paper or aluminum foil for effortless cleanup. Drizzle the sheet pan lightly with olive oil to prevent sticking and ensure even browning across all vegetables.

Combine diced onion and minced garlic in a small bowl, then scatter across the prepared sheet pan in a single layer. Roast for 5 minutes until fragrant and just beginning to soften, creating an aromatic base for your sheet pan veggies.

Remove the sheet pan from the oven and add cubed eggplant, sliced zucchini, yellow squash, and chopped bell peppers in an even distribution across the surface. Drizzle everything with the remaining 1 tbsp olive oil, then sprinkle with dried basil, oregano, salt, and pepper, tossing gently to coat all pieces evenly.

Return to the oven and roast for 15 minutes, stirring halfway through cooking to ensure uniform browning and heat distribution throughout the sheet pan ratatouille family summer recipe. The vegetables should be starting to caramelize and release their natural juices.

Whisk crushed tomatoes and tomato paste together in a bowl, then pour the mixture over the roasted vegetables, stirring everything together gently. Return to the oven for 15 more minutes until all vegetables are fork-tender and the sauce has thickened slightly, about 2-3 minutes longer if excess liquid remains.

Remove from the oven and let rest for 5 minutes before garnishing with fresh chopped basil and additional salt to taste if needed. This resting period allows flavors to meld beautifully, and the residual heat finishes cooking any particularly thick vegetable pieces.