In a blender or food processor, pour the two cans of tomatoes and blend until smooth. In a large pot, melt the butter over medium heat. Add the flour whisking until smooth, then slowly add half of the milk whisking until smooth, add the rest of the milk and continue to whisk over medium/high heat until it thickens. Add the blended tomatoes and whisk to combine, letting it heat and thicken. If it’s too thick at this point, thin it with more milk. Add salt and pepper to taste and enjoy!