Add the vegan butter to a pot and melt over medium heat. Add the chopped onions and celery, and sauté until the onions are soft and translucent.
Add the crushed garlic, red pepper flakes and rosemary and sauté for 2 minutes until the garlic is fragrant.
Add the potatoes and broccoli florets and gently toss them together. Add the vegetable stock and bring to a boil.
Reduce the heat, cover the pot, and simmer until the potatoes are soft and cooked, stirring occasionally. This should take about 30 minutes.
Remove the pot from the heat and remove the rosemary stalks.
Then, stir in the nutritional yeast and coconut milk.
Blend the soup using an immersion blender for the most effortless blending, or if you don’t have an immersion blender, you can use a regular blender. You’ll need to let the soup cool a bit and then transfer it in stages to your blender jug, blend it, and then when it’s all blended, return it to the pot.
Add sea salt and black pepper to taste.
Serve with a sprinkle of crushed black pepper and crusty bread on the side.