Melt the butter/heat the olive oil in a large pot over medium heat
Add the chopped leeks and cook until they’ve shrunk down a bit and are cooked and sheeny. (Kind of like caramelized onions). About 10 minutes.
Add the garlic powder, garlic, and onion powder and mix until incorporated
Then add the potatoes, and cover them with the vegetable broth
Bring to a boil and then lower to a simmer over medium-low heat until you can poke the potatoes easily with a fork, about 20 minutes
With an immersion blender, blend everything together until velvety and smooth. don’t be afraid to over-blend. Better over- than under-blended in this case.
Add lemon juice and mix in. Add salt to taste.
Serve with freshly ground pepper on top.