The Perfect Soup - Healthy, Delicious Creamy Kabocha Squash Soup

I love soup. A cold soup in summer and a hot soup in winter are wonderful comfort foods. The best soups for me are ones that not only nourish but delight with layered flavors.  In summer a light and spicy watermelon-gazpacho takes the edge off soggy, sultry days. In cool weather, a satisfying soup of roasted squash is filling and refreshing.

With cooler weather approaching, a great many varieties of squash will be available in farmers markets. My favorite is the Japanese squash kabocha. A squat round squash with a flecked dark green outer skin, the flesh can be bright yellow or pumpkin orange. Similar to butternut squash, kabocha is sweeter and cooks more quickly.

I first enjoyed kabocha as light and crispy tempura at Yabu, a sushi bar in West Los Angeles. Included in an order was a sheet of seaweed, shrimp, shiso pepper, shiitake mushroom and kabocha. With only one slice of each to an order, my wife and I divided up the sampling but we always shared the sweet flavored kabocha.

Over the years, I tried preparing kabocha using different techniques. Boiling, steaming, roasting and deep frying. Boiled, the flesh absorbs too much water and becomes soggy. Deep frying is specific to tempura. Steaming softens the flesh. Roasting puts a crust on the outside.

I discovered that combining steaming and roasting created full-of-flavor, firm fleshed pieces. We serve steamed & roasted kabocha as a side dish to accompany grilled fish, chicken and meat. Cut into bite sized pieces, the kabocha is delicious added to soups, stews and braises. Pureed, kabocha creates a deliciously sweet and creamy soup.
For a pot-luck brunch at a friend's beach house, I decided to make kabocha soup. Still out of season locally, kabocha can usually be found in Asian, Latin and Persian markets.

To make a vegetarian/vegan soup, I used homemade vegetable stock. Homemade chicken stock can also be used because of its light flavor but I wouldn't use beef or seafood stock because they are too strong.

Homemade stock is much preferable to store bought because the flavors will be cleaner and the salt content will be much lower. We always have a good supply of homemade stocks in the freezer so I can make soup at a moment's notice.

Making vegetable stock is easy, with a little planning and one important kitchen tool: a food mill. Vegetable stock can be made with a variety of your favorite vegetables. Dice and simmer carrots, celery, onions and mushrooms for an hour with water until soft. Run the liquid and softened vegetables through a food mill to create a delicious stock with pulp, ideal for making soups and sauces.

An alternative method is the one I prefer. During the week I collect vegetable trimmings as I prepare salads and stir fries. I place them into a sealed bag in the freezer. When we have corn on the cob, we put the cobs in the freezer as well. Once there is a large amount collected, all the trimmings and cobs go into a large stock pot. I add enough water to cover and simmer uncovered for an hour or more until the stock has flavor. Then the trimmings, except the corn cobs, go into the food mill as described above. I freeze stock in 16 and 8 ounce sealed containers for times when I want to make a soup or a braise.

Richly Flavored Kabocha Squash Soup

If kabocha is not available, butternut and acorn squash are good substitutes. But they are not as sweet.

If shiitake mushrooms are not available, brown and portabella mushrooms are good substitutes.

The slow roasted tomatoes are easy to make. While you sleep or read or work around the house, the tomatoes cook in the 225 F oven. Slow roasting removes the tomato's water, concentrating the flavors, bringing out sweetness. After the tomatoes are removed from the oven and cooled, they can be refrigerated or frozen in an air tight container. Remove the paper thin skins before using.  The skins aren't edible but they add a wonderful flavor to vegetable stock.

To puree the soup and create a creamy texture, use an immersion blender or a blender. I like the immersion blender because of the easy clean up. When blending, no need to remove all small vegetable bits. A bit of texture is good.

As a topping, homemade croutons or charred greens (escarole, spinach or kale) and onions are good.

Serves 4 (entree) or 8 (starter)

Time to prep: 30 minutes

Time to cook: 60 minutes plus 6 hours to make slow roasted Roma tomatoes

Total time: 90 minutes plus 6 hours to make slow roasted Roma tomatoes

Ingredients

2 large Roma tomatoes, washed, stem removed, cut in half from stem to tip

1 1/2 pound kabocha squash, washed, skin on, quartered from top to bottom, seeds and pulp removed and discarded

1 cup sliced mushrooms, preferably shiitake, washed, pat dried

1 medium and 1 small yellow onion, washed, root and stem removed, skin removed and discarded

2 cups kale leaves, washed, stems removed, finely cut

6 cups homemade stock, vegetable for vegan and vegetarian soup or chicken stock

1 cup escarole, spinach or kale, washed, finely shredded

2 tablespoons extra virgin olive oil

1 teaspoon kosher salt

1/4 teaspoon sea salt

1/8 teaspoon freshly ground black pepper

Pinch cayenne (optional)

Directions

Before you go to bed or while you are working around the house, preheat the oven to 225 F. Place the halved Roma tomatoes on a Silpat or parchment sheet on a baking sheet. Drizzle with olive oil. Place in the oven 5-6 hours. Remove when the tomatoes are still plump and they have reduced their size by half.

Remove tomatoes and allow to cool. If using immediately, remove the skins and discard or use to make vegetable stock. Finely chop the roasted flesh and reserve.

Place 2" water and kosher salt into the bottom of a large pot. Place a steamer basket into the pot with the quartered kabocha on top. Cover. Bring water to boil. Cook 10 minutes or until a pairing knife can be easily inserted into the flesh. Remove and cool.

Using a pairing knife, remove the kabocha skins and discard. Place the steamed kabocha on the Silpat or parchment sheet covered baking sheet. Drizzle with olive oil. Place into preheated 350 F oven. Cook 30 minutes. Remove and allow to cool.

Heat a tablespoon olive oil in a large pot. Sauté but not do not brown mushrooms, medium onion slices and kale. Cut roasted kabocha into quarter sized pieces and place into the pot. Add stock. Stir and simmer 30 minutes.

Heat a teaspoon olive oil in a small frying pan. Saute the sliced small onion and chopped escarole, spinach or kale until charred. Remove and reserve.

Taste soup. Adjust seasoning with sea salt and/or black pepper. Taste and add cayenne (optional).

Using an immersion blender or blender, puree soup until smooth allowing for some vegetable bits.

Serve hot with the charred escarole and onions sprinkled on top.