1: Preheat the oven to 190C.
2: Sauté sliced onion and broccoli stalk in olive oil for 5 minutes, then add garlic and sauté for another minute.
3: Pour in stock and cream, and let simmer for 5 minutes before removing from the heat.
4: In a large pot of boiling water, submerge broccoli florets and cavolo nero for 2 minutes.
5: Remove and separate, putting the cavolo nero into a blender along with the creamy onion mixture, mustard, and nutritional yeast, and blend until smooth.
6: In the pan that the creamy onion mix was in, pour beans and broccoli florets and then cover with the green sauce.
7: Mix well and top with cheese, then bake in the oven for 10 minutes until bubbling and golden.
