Preheat oven to 375°F (190 C). Combine basil, parsley, sun-dried tomatoes and garlic in a food processor; pulse until finely chopped. Add olive oil, water, lemon juice, lemon zest, salt and pepper; pulse until smooth. Adjust seasonings to taste.

Toss tomatoes with 3 tbsp (45 mL) pesto. Arrange in a foil-lined roasting pan. Roast for 25 minutes. Remove half of the tomatoes. Mash the remaining tomatoes roughly; stir in remaining pesto.

Meanwhile, cook spaghetti according to package directions. Add hot spaghetti and reserved tomatoes to roasting pan; toss well to coat. Serve with Parmesan cheese (if using).

Tips
– Use a potato masher to break up the tomatoes easily.
For a preparation shortcut, replace the homemade pesto with 2/3 cup (150 mL) any favourite bottled pesto.
– Replace the sun-dried tomatoes with 2 tbsp (30 mL) each pine nuts and Parmesan cheese for a traditional basil pesto.