Kale and Cabbage Soup

Combine tomatoes, butter, dried minced onion, salt, and black pepper in a small saucepan over medium heat; cover and simmer for 10 minutes.

Meanwhile, heat olive oil in a stockpot over medium heat. Add celery, onion, garlic, and bay leaves; cook and stir until onion is translucent, about 5 minutes. Add tomato mixture; cook and stir another 5 minutes.

Remove and discard bay leaves; add water, green cabbage, beef base, herbes de Provence, and red pepper flakes. Partially cover the pot and simmer until cabbage is very tender, about 20 minutes.