01 - Combine chopped salmon, onion, garlic, dill, parsley, egg, breadcrumbs, Dijon mustard, lemon zest, salt, and pepper in a large bowl. Mix until just combined, taking care not to overwork the mixture.
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. Cook salmon balls in batches, turning occasionally, until golden brown and cooked through, about 8 to 10 minutes total. Transfer to paper towel-lined plate to drain.
04 - Blend avocado, Greek yogurt, lemon juice, olive oil, garlic, cilantro or parsley, salt, and pepper in a food processor or blender until smooth and creamy.
05 - Serve salmon balls warm, accompanied by the creamy avocado sauce for dipping or drizzling.