Sweet Potato Cauliflower Soup

Recipe i followed: http://www.allysonkramer.com/2011/10/sweet-potato-cauliflower-soup/

Now if you looked at the recipe link i provided, i'm sure the first thing you notice is that the color is different.
That is because i'm sure they used Yams that people tend to still call sweet potatoes. Yams are the orange ones, like the ones used during thanksgiving for candied yams. I did try looking up about sweet potatoes and yams, and just furthered confused myself as there's different types of sweet potatoes and wasn't finding exact what i was looking for.
Well I had wrote down sweet potatoes on the shopping list, so my mom got me real sweet potatoes instead of yams. I wasn't thinking about it when i wrote it down about the color difference. Will probably try again using yams since i'm pretty sure that's what they really used based on the coloring. My sweet potatoes were probably also smaller than i needed since i think yams are usually larger on average.

There's everything i used for this soup. The amount of water to use was already in the pot.

My roughly slapchopped onions in the water with the sweet potatoes i peeled and cut. This ends up getting blended up so i didn't really care how neat the cuts were.

After i cooked the cauliflower. my first time cooking it this way.

Everything all cooked and added in before blending. Now i didn't want to wait for the cooling and using the blender, i used an immersion blender instead. then i didn't have to do it in 2 parts or reheat it. It does make me wonder if it would of gotten a lot thinner in texture if doing the blender.

Well in the end, everything i did for this, it was decent. I think maybe from using actual sweet potatoes, and them being smaller(though using one extra to make up for the sizes), the taste was kinda bland. I don't know what the difference off hand would be between using the sweet potato and yams for the taste. I read in the comments that people really like this soup, so i will try it again while using yams.

This way wasn't horrible, but me and my mom agreed that it was missing something. Maybe if someone tries it this way with a sweet potato instead of yams could figure out what that little missing bit is and let me know?