For pancakes, combine potato, leek, and water in a blender. Blend for a few seconds to turn into a slurry, you don't want it completely creamy, a few small bits are good.
Combine flour, salt, black pepper, bell pepper, and parsley in a medium mixing bowl and stir. Add potato slurry and stir well until combined. You will have a batter.
Heat a skillet over medium heat. Use a nonstick skillet, or use 1 teaspoon of medium heat oil to coat pan. Add a ladle of batter at a time to hot pan and cook until edges begin to dry out a bit and its starting to crisp on bottom, usually 1-2 minutes. Flip over and cook on other side, 2-3 minutes until browning and cooked through. Taste test for doneness. Transfer to a plate to keep warm and cook remaining pancakes.
If making ketchup, simply combine all ingredients tomato paste through water in a small sauce pan and whisk to combine. Simmer on low heat for 5-10 minutes until fragrant and bubbling and transfer to a bowl to cool. Store in fridge and use as needed.
You can add in other veggies like spinach, or use half sweet potato half russet potato. Serve with condiments of choice, though ketchup is the good ol American standby.