Begin by heating the olive oil in a large, heavy-bottomed stockpot over medium-low heat. Once the oil is simmering and fragrant, add the chopped onion, carrots, and celery. Sauté these aromatic vegetables until they soften slightly, about 8 minutes. This is the base of your soup, so take your time to let them develop their flavor.
Next, add the finely chopped garlic and sauté for an additional 30 seconds until fragrant. You’ll know it’s ready when you start to smell the delicious aroma filling your kitchen!
Now, it’s time to add the zucchini and green beans. Stir them in and continue to cook for about 4 to 5 minutes. The vegetables should start to soften but still retain some crunch. Keep stirring occasionally to prevent them from sticking to the bottom of the pot.
Once the zucchini and green beans are slightly tender, throw in the cauliflower florets and cabbage leaves. Stir to combine, and then pour in the beef stock, bringing the mixture to a high heat. We want to get this soup simmering!
As the soup comes to a boil, season with the bouillon powder and cayenne. Taste the broth during this step and adjust the salt and pepper according to your preference. This is your chance to make it just right!
Once simmering, reduce the heat to low. Cover the pot and let it cook until all the vegetables are fork-tender, which should take about 20 minutes. The longer it cooks, the more the flavors will meld together, creating a rich, comforting broth.
After the vegetables have reached that perfect tenderness, add in the washed spinach leaves. Stir them through until they wilt down, which will only take a minute or two.
Finally, remove the pot from heat and stir in the freshly chopped parsley and lemon juice. This adds a bright, fresh note that balances all the earthy flavors.
Adjust any final seasonings as needed, and serve immediately. You'll find that this Vegetable Soup not only satisfies your hunger but also warms your heart!