Heat a large Dutch oven or heavy-bottomed pot over medium-high heat. Add the coconut oil and swirl it around to melt and coat the base of the pot. Add the onion, ginger, garlic, red pepper flakes and 1/2 teaspoon salt. Saute, stirring occasionally, until the vegetables have softened, about 5 minutes.
Add the tomato paste and stir to coat the vegetables. Add the crushed tomatoes, vegetable broth, coconut milk and another 1/2 teaspoon salt. Bring the mixture to a boil, then turn the heat down to low, cover and let simmer for 20 minutes.
Turn off the heat and remove the lid. Use an immersion blender to blend the soup until it's smooth. (This could alternatively be done in a blender.)