Heat the oil in a large stock pot over medium heat. Add the onion and yam and cover, stirring occasionally, until onion begins to turn translucent, about 3 to 5 minutes. Add the carrots, celery and garlic. Cover and continue cooking, stirring occasionally, until all vegetables have softened but are still al dente, about 3 to 5 minutes.
Add half the broth, vinegar, avocado, and paprika to a small blender and blend until smooth. Add this mixture to the pot with the vegetables along with the remaining ingredients and stir well. Reduce heat, cover, and cook at a gentle boil for 15 minutes. Uncover and continue cooking, stirring occasionally, until chowder has thickened to desire level, about 10 to 15 minutes.
Taste chowder for flavor and add more sea salt to taste. Serve chowder with sliced avocado, red pepper flakes, and dried parsley.
*For smoky flavor, use smoked paprika. I use sweet paprika.