So I made the soup, with a few small modifications which I will note here, and then I tried to make a gluten free version of the parmesan crackers by simply replacing the flour in the original recipe with gluten free flour. The results were a disaster: a large pile of rather expensive parmesan grit.
Not one to give up, I went to the book Great Gluten Free Baking, where I found a recipe for stilton and rosemary biscuits (biscuits here in the British sense of cookies, not in the American sense of rolls). I promptly replaced the stilton with parmesan, the rosemary with thyme and added one more egg yolk in order to sort out the liquids, and the results were great: a delicious crumbly cracker that practically melted into the soup.
So here I give you my version of the soup and my gluten free version of the crackers, but of course you can try the original. You can also, of course, serve the soup without the biscuits.
Asparagus Soup with Crumbly Parmesan Biscuits
Ingredients (for 4-6 portions):
For the soup:
- 2 tablespoons unsalted butter
- 1 medium onion, thinly sliced
- 1 1/2 pounds asparagus, cut into 1-inch (2 cm) pieces
- 4 cups of vegetable broth
- handful of mint leaves
- handful of flat leaf parsley
- 3/4 cup light cream (you can also use heavy or whipping cream if you prefer, but in a soup I see no reason to add all that extra fat)
- 1/2 cup frozen baby peas, thawed
- Salt and freshly ground pepper
For the biscuits:
- 75 grams (about 3 oz) grated parmesan cheese, preferably good quality
- 75 grams (3 oz) butter
- 100 grams ( 3.5 oz) white rice flour
- 1 tablespoon polenta or yellow corn flour
- about 1 tbsp chopped fresh thyme or 1 tsp dried thyme
- 2 egg yolks
For the Soup:
1. Melt the butter in a large pot. Add the sliced onion and cook over moderate heat, stirring, until the onion is soft - about 6 minutes. Add the asparagus pieces, cook for another minute, and then add the broth and simmer about 10 minutes or until the asparagus is soft.
2. Chop the parsley and mint finely and add to the soup. Puree the soup using a hand-held blender or in batches in a regular blender or food processor. Make sure it's very smooth and you get all those asparagus pieces.
3. If you used a regular blender to puree the soup, return it to the pot. Add the cream and peas and reheat the soup. Season with salt and pepper. Serve with the parmesan biscuits, or by itself.
For the biscuits:
1. Place all of the ingredients except the egg yolk in a food processor and whiz until combined (you can also do this by hand in a large bowl, but it does work a bit better in a food processor). Add the yolks and continue to whiz/mix until the mixture comes together as a soft dough.
2. Roll the dough into a sausage shape, about 15 cm (6 inches) long (if you need, use a bit of rice flour to prevent sticking, but I didn't find that necessary). Wrap in plastic wrap and chill for 30 minutes. Meanwhile, preheat oven to 200 C/400 f.
3. Unwrap the dough and slice into 20 discs. Place the discs on baking sheets which have been lightly greased or have parchment paper on them. Bake for 12 minutes, or until the biscuits are golden. Cool completely before trying to remove from the sheet. Note: the biscuits will be quite crumbly in texture. This is a good thing. It allows them to almost melt into the soup, leaving just a slight crunch and a lovely cheese flavor. But do be careful with them or they will fall apart.