01 - In a large bowl, combine chopped salmon, onion, garlic, dill, parsley, egg, breadcrumbs, Dijon mustard, lemon zest, salt, and pepper. Mix until just combined; do not overwork the mixture to maintain tender texture.
02 - With damp hands to prevent sticking, shape the mixture into small balls using approximately 1 heaping tablespoon per ball. Arrange on a tray until ready to cook.
03 - Heat olive oil in a large nonstick skillet over medium heat. Fry the salmon balls in batches, turning occasionally, until golden brown and cooked through, about 8–10 minutes total. Transfer to a plate lined with paper towels to drain excess oil.
04 - Combine avocado, Greek yogurt, lemon juice, olive oil, garlic, cilantro or parsley, salt, and pepper in a food processor or blender. Process until smooth and creamy, scraping down sides as needed.
05 - Arrange warm salmon balls on a serving platter and drizzle with the creamy avocado sauce or serve sauce on the side for dipping. Garnish with additional fresh herbs if desired.