On low to medium heat, stir all of the ingredients together in a large saucepan or small pot. If you like more tomato flavor, stick with 1 ½ cups milk. If you like it more creamy, use 2 cups of milk.
Stir until well combined and allow to simmer for 5-10 minutes, until the sauce is thick. Add milk if desired and adjust seasonings to taste.
Serve with grilled cheese sandwich or salad.
Notes
* If using diced or stewed tomatoes, you may want to use an immersion blender to blend until the desired consistency is reached.** This is a mild soup; but feel free to reduce or omit the crushed red pepper flakes if you don’t like a little spice.