Power Green Soup
In a 5- to 6-quart pot, heat oil over medium heat. Add onion and celery. Cook until soft and translucent, about 8 minutes. Add ginger, horseradish and garlic; cook 1 minute. Gradually add mustard greens, collard greens and kale. Cook until very soft and wilted, about 5 minutes. Add stock.Advertisement
Increase heat to medium-high and bring mixture just to a boil. Reduce heat and simmer, uncovered, until everything is very soft, about 20 minutes. Stir spinach into soup until wilted. Working in batches, puree soup in a high-powered blender until very smooth. Season to taste with salt and pepper. Serve with lemon wedges for squeezing over each bowl, if desired.
For the best results, make this soup in a high-powered blender. Budget models may struggle to fully puree the fibrous greens.