Pure magic, this soup is. I first enjoyed it at a dinner party that was hosted by a chef friend of ours, Sam. He’s actually not cooking in restaurants anymore, and is training to be a surgeon (most interesting man alive? I think so), but wow was that meal something else – one of the best I’ve had in all my years living in Indianapolis, I can tell you that. When I walked in, he was standing at the stove, attentively stirring a pot of some dreamy looking concoction with the most attractive golden glow. “It’s soup – just two ingredients! Literally! Only two things – just kabocha squash and onions. That’s it.” It was this Two-Ingredient Squash and Caramelized Onion Soup that he was preparing, and I was pretty transfixed by it.
He explained, albeit quickly (lots of people milling about at the time), that you don’t need anything but those two core ingredients to make a killer soup, and that really it’s just a matter of getting the seasoning (salt/pepper) and consistency right. I immediately understood that. Because let’s be honest guys, there’s a fine line between a restaurant-quality pureed soup and baby food. The difference is really in the thinning out of that puree, getting it nice and smooth/silky and getting that salt level just right. Also, I’ve never seen any baby food that’s chock full of onions … pretty sure that’s not a thing.
What is Kabocha Squash?
Kabocha squash is at the very top of my most beloved seasonal produce list, sharing top honors with heirloom tomatoes and Concord grapes. A kabocha (Japanese pumpkin) resembles an acorn squash somewhat, being similar in size/shape and with their deep green skin. It’s the texture of a kabocha, however, that makes it perfect for soup like this. It becomes liquid velvet – the inherent creaminess and richness of the flesh blends into something that seems like it should have cream or milk in it, but you really don’t need to add anything like that. We’ll simply build the soup with water and salt, adding a little of each gradually as we stir and stir. It’s a beautiful thing.
You’ll notice in this recipe that I’m asking you to pre-roast the squash before you cut into it. I always do this with my fall and winter squash, as it makes the cutting of things SO MUCH EASIER. Truth be told, as much as I love eating and cooking with them, I don’t love cutting squash. It’s not easy, y’all. This is the best/safest way to do it. A little time in the oven will soften the skins enough to make slicing, peeling and cutting a breeze.
Now, that being said, can you add more ingredients to this soup? Of course you can! If you do want to add some cream or maybe some vegetable stock, in place of/in addition to the water, go for it. You could add some roasted garlic and dried or fresh herbs, and I think some caramelized apples would be really nice, blended up in the mix as well. But my point in sharing this recipe – with just the two superstar ingredients – is to tell you that it’s not really necessary. I actually did test this soup with half and half, instead of water, and while yes, it was different – it was not better.
So, in the name of the My Kitchen Little quest to give you as many simple, few-ingredient recipes as I can, I am so pleased to share this one with you.
Two-Ingredient Squash and Caramelized Onion Soup
At only two core ingredients, this soup is pure magic. A luscious, velvety puree of my favorite of all the squashes – the kabocha – and sweet, mellow (mostly) caramelized onions. Thanks to the inherent creaminess and built-in texture of the squash, no actual cream is needed for this soup. It’s just squash and onions and it will knock your socks off (I don’t count cooking oil and salt/pepper as ingredients). It’s gorgeous served/passed in shot glasses, as a small starter before a big meal, or topped with anything you like, as an accompanying side to a main course.
Ingredients
3 kabocha squash
2 Tbsp olive oil
3 medium-sized sweet onions, thinly sliced (such as Vidalia or Walla Walla)
Salt and pepper, to taste and as needed
Instructions
Preheat your oven to 350 degrees F. Place the squash directly on your oven racks and allow them to cook for 30 minutes. This will make it SO much easier to cut and peel them (totally worth this step). Once they’re cool enough to handle, cut the tough outer skin/peel away and slice in half. Remove the seeds and then cut the squash into small, roughly 1-inch pieces.
Meanwhile, while the squash are roasting away, add the oil to a large, deep pot set over medium heat. Add the sliced onion and 1 tsp salt and cook, stirring frequently, until they have softened tremendously and turned a medium-brown color; about 25 minutes. We’re not fully caramelizing them here – it’s a light caramelization.
Once the onions have cooked for about 25 to 30 minutes, add the squash into the pan with the onions along with ½ cup water and ½ tsp salt. Stir and cook, covered, for 5 minutes. Remove the lid, stir and mash up the squash and add another ½ cup water. Cover and cook for another 5 minutes. Transfer the mixture to a blender. Blend until totally creamy and smooth. Pour back into the pot.
Taste the mixture and add salt/pepper as needed. Add another 1 cup water and stir! Stir! Continue cooking the soup and adding water until you get it to a true pureed soup consistency (not thick baby food). You can determine the consistency that best suits your tastes here. The soup will reduce and thicken the longer you keep it over the heat, and also, if you get it too thin (if you add too much water), just let it cook a little longer. Serve as it is or with toppings of your choice such as toasted nuts, sliced apples, and maple syrup (pictured).
