Prepare the ingredients. I used a leftover piece of broccoli, including the peeled stem, cut into small cubes so it cooks evenly. Cut the celery into pieces.

Cut the carrot into quarters and the zucchini into half-moons. Chop the onion. Melt the butter over medium heat.

Add the chopped onion. When it turns translucent, add all the vegetables and stir well to coat them with the butter. Cover and let them sweat to release their aroma.

Chop the parsley. When the vegetables are partially cooked, add enough water to cover them, along with the parsley and a little salt.

Cover and cook for 20 minutes, until everything is well cooked. Blend in batches and return to the pot, passing the soup through a strainer.

This is important because celery often leaves a lot of fiber that can give the soup an unpleasant texture. Check the seasoning, add salt and pepper to taste. Serve the soup garnished with sesame seeds for extra nutrients.