Peel and finely mince enough yellow onion to yield about 1/2 cup. If you prefer a milder onion flavor, soak the minced onion in cold water for 5 minutes, then drain and pat dry.

Prepare scallions and chives

Thinly slice 3 scallions (white and green parts) and finely snip 2 tablespoons fresh chives. Reserve about 1 tablespoon chives/greens for garnish.

Grate or mince 1/2 tsp garlic very finely so it disperses evenly through the dip.

Assemble Dip Base

In a medium mixing bowl, combine 1 1/2 cups sour cream, 1/4 cup mayonnaise and 1/4 cup plain Greek yogurt (if using). Stir until smooth and uniform.

Add 1 tablespoon fresh lemon juice to brighten flavors and whisk to incorporate.

Combine & Season

Add the prepared minced onion, sliced scallions, 1/2 tsp grated garlic and 2 tablespoons chopped chives to the dip base.

Mix in 1 tsp dried onion flakes (or onion powder), 1/2 tsp dried parsley (if using), 1 tsp fine sea salt, 1/2 tsp black pepper, 1/2 tsp Worcestershire sauce and 1/4 tsp hot sauce (optional). Stir thoroughly to distribute ingredients evenly.

Taste and adjust seasoning: add up to 1/4–1/2 tsp more salt or a few drops of lemon juice if brighter acidity is desired.

Rest & Refrigerate

Transfer dip to an airtight container or cover the bowl with plastic wrap. Refrigerate for at least 1 hour, preferably 2–4 hours, to allow the onion and herbs to meld and flavors to develop.

If making a day ahead, stir again before serving and adjust seasoning if needed.

Serve

Spoon dip into a serving bowl, sprinkle reserved chives/scallion greens on top for garnish. Serve chilled with potato chips, vegetable crudités, crackers, or use as a sandwich spread.

Store leftovers covered in the refrigerator for up to 4 days. Stir before serving.