Kale and Watercress Soup Recipe | Epicurious

Ingredients

• 2 tablespoons unsalted butter
• 8 white button mushrooms, cut into 1/4-inch slices
• 6 shallots, sliced
• 3 garlic cloves, grated
• 2 bunches kale, stems and center ribs discarded, cut into 1-inch strips, divided
• 1 tablespoon kosher salt
• 1 teaspoon white pepper
• 3 Idaho potatoes, peeled and cut into 1/4-inch-thick slices
• 1 cup heavy cream
• 1 cup whole milk
• 2 bunches watercress, trimmed, plus more for garnish
• 3 tablespoons reduced-fat sour cream (optional)
• 8 slices whole-grain bread (optional)