In a medium pot, heat the oil over medium heat. Sauté the onion until soft.
Add the pumpkin, sweet potato & red bell peppers and saute for 3 minutes.
Add the can of tomatoes, plant based milk, vegetable broth & vegetable stock cube.
Cover the pot and simmer for 25 minutes.
Let the vegetables cool for about 10 minutes.
Add vegetables to a blender in two separate batches and pure until smooth. If using an immersion blender, puree in the pot.
Return to the pot and season with kosher salt & black pepper. Heat soup again if needed.
Serve hot.