This is an adaptation of the recipe found here. It is delicious, easy (but time consuming) and perfectly seasoned. This soup freezes beautifully. Do not add cream until ready to serve.
To make four quarts:
1/4 cup vegetable oil
2 pounds yellow onions (about 2 large), diced or sliced
12 cups (four 28-ounce cans) peeled San Marzano tomatoes with their juice
OR 7.5# frozen tomatoes from garden, peeled and chopped
2 cups heavy cream (less, or none, 2019)
2 tbsp light brown sugar
1 tbsp kosher salt
1/2 tsp cinnamon
1/4 tsp ground cloves
1/4 tsp ground nutmeg
1 tsp ground cardamom
1/2 tsp cayenne pepper
1/4 tsp freshly ground black pepper
baking soda to control acidity as needed at end
Heat the vegetable oil over medium heat. Add the onions, and stir to coat with oil. Cook, stirring from time to time so they don’t stick to the pan, until they start to brown. Reduce the heat to medium-low, and continue cooking until they caramelize and turn dark brown, about 45 minutes up to 75 minutes.
When the onions are caramelized, add the tomatoes, then puree the soup in a blender in batches until perfectly smooth. Pour the puree into a stockpot.
Add the sugar, salt, allspice, cardamom, cayenne and black pepper, and stir to combine.
Bring the soup to a boil. Reduce the heat, and simmer the soup for 30 minutes to cook the tomatoes and let the flavors develop, stirring frequently to prevent scorching. Add the cream and stir well.
Serve as is, or with a dollop of pesto or a drizzle of heavy cream.
2017 – I made half recipe. It yielded only 5 cups liquid before adding the cream, so I only added 3/4 cup instead of 1 cup. This was plenty of cream, and it was delicious. I think the soup cooked down quite a bit during the 30 minutes of simmering.