How to Make It
Melt butter in a Dutch oven over medium-low heat. Add fennel, garlic, and 1/4 teaspoon salt; cover and cook 20 minutes or until very tender, stirring occasionally. Increase heat to medium-high. Add turmeric; cook 30 seconds. Add wine; cook 1 minute. Add golden beets and 6 cups water. Bring to a boil; cover, reduce heat, and simmer 1 hour or until beets are tender.
While soup simmers, combine Chioggia beets, juice, sugar, and cilantro; let stand 30 minutes. Drain.
Heat a large cast-iron skillet over high heat. Add amaranth; cook 1 minute or until toasted, shaking pan constantly. Pour into a bowl.
Place half of soup in a blender. Remove center piece of lid (to allow steam to escape); secure lid on blender. Place a towel over opening in lid. Blend until smooth. Pour into a bowl. Repeat with remaining soup mixture. Stir in remaining 1/4 teaspoon salt and red pepper. Spoon mixture into shallow bowls. Top with pickled Chioggias; sprinkle with amaranth.