In a large bowl, mix the squash with 4 cups of the water and the2 tablespoons of salt. Set aside for 40 minutes. Drain the brineand allow the squash to dry in the colander.
Meanwhile, in a medium colander, toss the kale with 2teaspoons of the salt and set aside for 15 minutes.
Using the colander, rinse off any excess salt with water.
In a large bowl, combine the squash and kale with the chilipepper flakes, ginger, garlic, and toss until the mixture is wellcombined. Place the mixture into a quart-sized container with atight lid.
Mix mushroom broth with sugar until the sugar isdissolved. Ladle the broth mixture into the container until 1/3 ofthe contents are covered.
Allow the mixture to ferment at room temperature for 2-3 days.
Refrigerate and enjoy within 1 month.