In a mixing bowl, combine the softened cream cheese, finely shredded sharp white cheddar cheese, light mayonnaise, and plain Greek yogurt. Using a hand mixer or whisk, blend these ingredients until they are smooth and creamy.
Stir in the fresh lemon juice and McCormick Guacamole Seasoning Mix.
Gently fold in the flaked smoked salmon, ensuring it is evenly distributed throughout the dip. If the mixture is too thick, add 1 to 2 tablespoons of milk.
Add the chopped green onions, reserving a little for garnish. Mix gently to incorporate the onions without breaking up the salmon too much.
Transfer the dip to a serving bowl and sprinkle the reserved green onions on top. Cover and refrigerate for at least 30 minutes before serving.
