First thing that comes to mind are Veggie Straws. Looking at the ingredients list, it seems like they use a mixture of potato flour, potato starch, and corn starch with vegetable puree (tomato paste or spinach powder for the red and green straws respectively). The batter is then fried up like a french fry, but has a texture closer to a potato crisp (ie: Pringles).
I imagine you could experiment with a mix of potato flour, potato starch, corn starch, and whatever puree you want to make various "french fries" out of them
I remember seeign this on /r/FoodPorn! If I remember correctly, it's just agar agar with some water and vanilla sugar.
Took a look on the internet and yep, here it is! It's called a unicorn tear, apparently.