Loaded baked potato soup is one of those dishes that has some contradictions built into it. You want it to be clean-tasting, but still over-the-top with flavor. You want it rich, packed with cheese and dairy, but you don't want it so heavy or gummy that it glues your mouth together. And of course you want it to have all the hearty, roasted flavor of a good baked potato, but still come in soup form. As a dish that's traditionally packed with cream and butter, making the whole thing vegan is an added challenge.
Let's get one thing straight right off the bat: When I say "fully loaded" baked potato soup, I mean loaded. Most so-called loaded soups are nothing more than baked potato purée with a cursory pile of bacon, chives, sour cream, and grated cheese sprinkled on top just before serving. I want that flavor in the soup. Nutty, cheesy tang, a touch of smoke, and plenty of chives or scallions with every bite. That's how I'd want my regular loaded baked potato soup, and that's how I'm gonna make my vegan version.
Fortunately, with some lessons I've learned from both making really good potato-leek soup and from the vegan nacho cheese sauce recipe I developed last year, a lot of that work is already done. It's largely just a question of tweaking and refining.
For my first attempt, I tried to go simple: I roasted a few potatoes until completely tender, made a batch of my vegan nacho sauce, thinned it out with a bit of almond milk, ran the potatoes through a ricer, and stirred them into the pot along with some sliced chives, scallions, and crispy vegan mushroom bacon.
The soup was good, but the flavor and texture weren't quite where I wanted them. My nacho-style cheese sauce, with its pickled jalapeños and heavy spicing, is simply too distinctive. I started to think of other ways to get a milder cheesy flavor. I know that many folks like to use puréed cauliflower in vegan versions of macaroni and cheese, which makes sense: it has a sort of nutty, slightly funky aroma that could form as the backbone to a deeper cheesy flavor.
I tried it, but it needed a boost. Roasting the cauliflower did the trick.
I split a whole head of cauliflower in half, tossed it in oil, then roasted it along with my potatoes in a 400°F oven for about an hour. The potatoes come out tender and the cauliflower richly caramelized, which further enhances its flavor, giving it a touch of sweetness.
For the rest of the cheeses sauce base, I started by sweating leeks, celery, and scallion bottoms (double the alliums to really boost that loaded baked-potato flavor) in vegetable shortening. Using a highly saturated fat like shortening, palm, or coconut oil gives the soup a richer, more creamy texture.
Next I added a touch of paprika and a chipotle chili packed in adobo. When used sparingly, both ingredients add some of that sharpness that good cheese has. Finally, I added some roasted cashews, which also give richness when blended. It's a much better option than the flour-based roux that folks often add to baked potato soup (I find it turns the soup heavy and gummy).
Once all the ingredients were sautéed, I blended them with the roasted cauliflower along with a small portion of the baked potato, adding almond milk for a thick, soupy texture. When you blend potato, it releases a ton of starch, giving the liquid that sort of sticky, stretchy texture that you get from melted cheese. It's an essential trick in my cheese sauce, and it worked well in this soup as well.
To keep the soup from becoming too heavy, I added the remaining potatoes by pressing them through a ricer, which gets them smooth without breaking out excess starch (too much starch can make the soup gummy). For a hint of that smoky bacon flavor, I also added a small dash of liquid smoke. I know some folks get squeamish about the stuff, but so long as you're buying a high quality, additive-free brand like Wright's, you're getting nothing but smoke and water.
After thinning out my soup with vegetable stock (water or more almond milk will work fine), seasoning it well with salt and pepper (potatoes LOVE salt), and stirring in some sliced chives and crumbled vegan mushroom bacon, it was ready to go.
I don't know about you, but for me, baked potatoes, cheese, and broccoli are a trio made in heaven, so I add a few steamed broccoli florets to the bowl. The easiest way to steam a small amount of broccoli? Place the chopped florets on a plate, cover with plastic wrap, and microwave on high for about a minute. They steam in their own moisture.
More of that crispy mushroom bacon, some thinly sliced scallions, and we're in business. Soup's on.