Pre-heat oven to 200°C / 392°F.

De-seed and cut bell peppers into quarters.

Brush bell peppers and garlic cloves with olive oil and place in a baking dish / tray.

Roast for 30 minutes, flip bell peppers, then roast for another 10 minutes.

Cut zucchinis into pieces and place in another baking dish / tray. Drizzle a little bit of olive oil all over and toss to coat.

About 10 minutes before the bell peppers are done, put zucchinis in the oven to roast.

When the vegetables are nearly done roasting, cook your spaghetti in a large pot of salted water according to instructions on package. Reserve 1/2 cup of cooking water for later. Drain and set aside in a large skillet.

Remove roasted vegetables from the oven. Transfer zucchini to the skillet with the spaghetti.

Transfer bell peppers and garlic to food processor or high-speed blender. Add sun-dried tomatoes, walnuts, salt and pepper, and process until almost smooth but still slightly chunky. Add cooking water from the pasta to thin out the pesto if desired, 1 tbsp at a time, until desired consistency.

Add pesto to the skillet. Toss with spaghetti and zucchini until mixed through. Warm up over medium heat until heated through. Divide into two servings bowls and enjoy!