How to substitute chicken broth in a vegetarian soup? I'm making minestrone soup (for the first time) and, on reading the recipe, it calls for chicken broth. Normally this is no problem, but my vegetarian brother is visiting this weekend and I was going to make enough to share. 


I'm assuming that chicken broth is non-vegetarian. I've asked him if he's willing to eat it, but for the time being I'm assuming it's verboten.
Not having the broth will obviously change the flavor. (I've never had minestrone before, so I wouldn't have any basis for comparison.) What should I replace it with for best results? Plain water, something with more body (red wine, which the recipe also calls for), or something a little more fun or exotic?
Your question seems to have two parts:


With what do I replace chicken stock to make the dish vegetarian and 
How can I add some zing to the dish for added interest?


To answer 1, I'd make a hearty vegetable stock from scratch. Recipies abound. Alternatively you could rely on a bought stock but I find that these can be overpowering and of course you have less control over the flavour. 

To answer 2, consider adding a dollop of pistou to each bowl of soup when serving. Freshly made pistou is easy and adds interest and flavour. See, e.g. http://www.bbc.co.uk/food/recipes/pistou_89874.