Actual vegan here, try any of the soups over at
Minimalist Baker,
Oh, She Glows,
Hot for Food, Thug Kitchen, or anything by
Isa Chandra Moskowitz (check out previews of her newest book,
Isa Does It, for some more soups, that book is killer).
Basics: thicken soups with fatty coconut milk, or puree part of the soup or a complimentary veggie and put it back in. Veggie fats like your favorite oils and Earth Balance are great subs for butter at any level of soup making. Don't use water, just buy vegetable broth or vegan bullion cubes like you would with any soup. You want this to be tasty for everyone, right? And don't forget to check that any bread (french/baguette, sourdough are safe, eggy things like brioche and challah aren't) or dippy thing you pair with is it vegan! Your vegan friend will thank you so much!
One of favorite soups to make is tomato soup, which is super easy. Take your favorite base tomato soup recipe and rather than adding cream, add fatty coconut milk or a vegan creamer that's not sweet or flavored (no vanilla hazelnut tomato soup!).
I dunno about other vegetarians/vegans, but I could NEVER get French Onion soup anywhere. Just use Earth Balance or even just your favorite oil and vegan friendly beef broth cubes (Kroger has some awesome ones in the natural section by a brand called Edward's and Sons I think). Bonus if you make your own big toasts and grab them a slice of vegan cheese to broil on top.
Tortilla soup is also super easy, and you can separate a big portion out for your friend and then put chicken in the rest so it gets the tasty flavors. Just remember to use veggie broth and vegan friendly fats. Ingredients will say contains milk and egg in the allergens, but also watch out for anchovies and honey.
Basically, you don't NEED to do lentil soup (but if you do, Minimalist Baker has a killer red lentil curry), and don't think of vegan as having to be healthy and for rabbits. Find a soup recipe that sounds awesome to you, and just swap out the broths and fats for vegan ones, and toss in any meat you think you need at the end after separating out the vegan portion.