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.
Stir in kidney beans and kale; partially cover the pot and continue cooking until heated through, about 15 minutes.
Kale and Cabbage Soup · Dinner Match Lab | Dinner Match Lab