Start by trimming the stems of the broccoli and chopping finely along with the onion and garlic.
Sauté the broccoli stems, onion and garlic in a large pot or Dutch oven set over medium-high heat in a knob of butter or a few tablespoons of oil until soft and fragrant.
Stir in the oregano, potatoes and broccoli florets and cook for another 5 minutes then pour in the stock/broth.
Season with salt and pepper then bring to the boil.
Reduce the heat and simmer with the lid ajar for 15-20 minutes or until the potatoes are tender.
Transfer the soup to a blender (or use an immersion blender) and blend with the spinach until smooth.
Blend in batches if you are cooking a big pot of soup.
Pour the soup back into the pot and add the cream.
Taste and adjust seasoning if necessary then simmer for 5 minutes then serve with garlic bread grilled cheese.