Almost every year, the first fall soup I make is butternut squash and apple soup, and every year, I know something is just not right about it. The soup is certainly delicious and comforting, but I always feel as if a flavor is missing - I finally realized what it is...the apple! Butternut squash has such powerful taste notes that while the apple helps to add some acidity and depth, it can never really shine in this fashion. As we know from my post about apple butter, I have a tremendous fondness for the caramelized apple, and that is what I want to come through. So I basically turned the apple butter into a soup and voilà - I had my desired flavor profile, and it was even more incredible than I imagined.
Okay, you might be thinking I took the apple butter and just added water; while that does seem like a simple way to make caramelized apple soup, it is not that easy. Though it is not much more difficult either! With not too many ingredients - white onions, apples, a little bit of oil, some white wine, water, thyme, oregano, a cinnamon stick, star anise, salt, cheddar, and hazelnuts - you can create the most decadent, velvety fall soup that will become your specialty of the season!
First, you will need to slice one large onion - do not dice it, for these smaller pieces have a tendency to brown too quickly. They will still taste great, but we want their sweetness to come through in this case, not the crispy onion appeal. We also want the onions to cook evenly and slowly so they can really develop their signature notes. In a wide soup pot (you want a good amount of surface area), add a splash of oil and cook the onions over low heat, stirring frequently so they do not stick.
As the sliced onions are cooking, you can prepare the apples. You will need about three large ones. Peel the skin and chop them into medium-sized pieces so that they will all have an opportunity to touch the bottom of the pan. Once the onions have turned to a beautiful deep gold (around 10-15 minutes), add in those apples! You can increase the heat a bit, but do not raise it much higher than medium. Continue to stir every few minutes so the apples can gain color all around and to prevent too much browning on one side or sticking to the bottom, just like with the onions. They should start to become very soft, but they should not break down entirely, for we do not want to cook out the moisture like with the apple butter - the juice sealed inside the browned apple flesh is now more concentrated and adds an intensity and purity to make this soup so memorable with apple-essence.
Some fond still may develop on the surface of the pan, so the next step is adding white wine to deglaze. You do not want to reduce it too much though so that it can add a bit more acidity and brightness to compliment the apples. Now, add water to cover, the herbs and spices (1 cinnamon stick and 2 pieces of star anise) in a sachet/tied in twine for quick removal later, and a pinch or two of salt. Let everything simmer together for about one hour, melding all the flavors into perfect harmony.
While the soup is cooking, cut the hazelnuts in half and toast them in a 325°F oven for about 10 minutes/until they become amber in appearance. You can also grate the cheddar cheese using the large grates on a box grater. For a nice serving of soup, you will need about 1/3 cup of cheese. Once these steps are done, prepare your immersion blender, put your bowl on a sheet tray (make sure the bowl is oven safe), and set your oven to broil - yes, we are going to gratinée the top to finish!
Once the soup's simmering time is up, taste it to verify it has enough layers of flavor for you - if you think it could use more spice, let it sit for a bit longer or even add in a few more cinnamon sticks or star anise. When you are fully satisfied, use your immersion blender to smooth it out. You can use a typical blender if you desire, but the immersion blender actually does not leave any lumps or graininess (and is faster to clean up!); the starch from the apples dissolves into the broth and yields a silky texture with a honeyed, dark blonde color you would not believe was achieved without the use of any cream. If you do run into trouble with getting the right smoothness, you can strain the soup, but hopefully you will not have to worry about doing so.
After blending, double check the seasoning - is there enough salt? Do you still want more cinnamon? If so, you can add in some ground cinnamon at this stage. Do you want more acidity? Squeeze in some lemon. Do you want a little heat? Try some black pepper.
We have arrived at the final steps - hooray! Ladle your soup into your bowl on your sheet tray. Cover the top with the grated cheddar in an even layer, put it in your broiler, and keep it inside until the cheese has turned golden brown and melty. Pull it out and garnish with the toasted hazelnuts. You are done!
Essentially this soup combines all of your favorite parts of French Onion Soup into a lighter, luscious version for the fall, focusing on the elegance of the cooked apple and enhancing it with the unmistakable goodness of caramelized onions. You will not be able to stop yourself from eating more than one bowl, so I highly recommend doubling or tripling the proportions depending on how many people are in your house - it will disappear instantly as soon as your friends and family find it, but here is a trick: hide some in your freezer just for you! Although it is not hard to put together and will make your kitchen smell divine, having some on hand for whenever a craving arises is definitely ideal!