Finely chop the onion and celery stalk, grate the carrot on the small holes of a box grater. Finely chop the garlic.
In a large pot, warm the oil over medium heat. Once hot, add the chopped onion, celery and carrots and dried spices (if you’re using fresh basil leaves, you can skip dried basil). Cook for about 10 minutes, stirring frequently.
Add the chopped garlic, cook for a minute.
Add the wine, cook, stirring, for a few minutes, until almost completely evaporated.
Add the tomato passata, crushed canned tomatoes and broth (broth is optional! only if you have time to cook the sauce about 40 minutes longer, so that the excess liquid can evaporate, the sauce with the broth will be tastier, but you can easily skip it if you don’t have time). Cook for about 30 minutes (partially covered) until the sauce thickens, stirring from time to time (especially at the end). Take the pot off the heat.
Season the sauce with balsamic vinegar, sugar and salt, and pepper to taste.
Add basil leaves (if using) and puree the sauce with a hand/immersion blender until smooth.
While the sauce is cooking, prepare the spinach and zucchini.
Preheat the oven to 220 °C / 450 °F / Gas 8, no fan (if you have a convection oven reduce the temperature by about 20° of follow the manufacturer's instructions).