Add red pepper, carrots, celery, red onion, garlic cloves, ginger, rosemary, palm oil, sweet potatoes and curry powder into a large pot. Stir and fry for 3 minutes.
Pour the vegetable stock into the pot and simmer for 25 – 30 minutes.
After 25 minutes, in a separate pot, melt the butter on low to medium heat. Once melted, add the flour and whisk it along with the butter until it become a thick paste like texture. Once thick, pour in the milk and continue whisking until the flour slurry mixture is nice and thick.
Pour the flour slurry into the soup pot and simmer for 5 minutes. (If you enjoy your soup chunky, you may serve at this point).
Blend the soup together for a smooth texture and serve with a warm dinner roll.