You can use any variety of canned tomatoes: crushed, diced or whole (peeled) . Keep in mind that the better the tomatoes, the better the soup.
I use crushed or whole tomatoes (they tend to have a better flavor), preferably with no added salt (so that I can better control the sodium). Nevertheless, if canned diced tomatoes with salt is what you have in your pantry, your soup will still taste great.
How to Make 3-Ingredient Vegan Tomato Soup
Begin by chopping the onion and then sautéing it in the oil. Cook and stir until the onion is a deep golden brown; the caramelization adds so much to the finished soup!
Next, I have a cheat.
Blending hot soup can be a royal pain if you do not have an immersion blender. Blending in a food processor or regular blender can lead to big messes (e.g., soup on the ceiling; been there, done that) and burns (I have the scars to prove it). High power blenders, such as Vitamix or Blendtec, have hot soup functions, but not everyone has one of these pricey appliances.
My solution? Blend the cold tomatoes with the sautéed onions. No burns, no food explosions from the hot-soup-steam, and no fuss. You can use a food processor or an ordinary blender. Easy!
Transfer the puree back to the pan used for cooking the onions and add 1-1/2 cups water and a bit of salt. Bring the soup to a low boil, then reduce to low and simmer, uncovered, for 35 to 40 minutes until the soup is thickened slightly and deep red in color.
You’ve got dinner, friends. Tomato soup needs nothing fancy as accompaniment. Think crackers, toast, and/or some bits and bobs (salad, cheese, etc), leftover from previous repasts, to round things out.
Mondays need meals like this. Happy eating, everyone!