Squeeze the spinach:
Place the thawed spinach in the center of a dishtowel. Gather the edges of the towel together. Hold the bundle over the sink and twist and squeeze out as much water as possible. Set aside.
Bowl of Defrosted Spinach for Spinach Dip Recipe
Moisture Squeezed from Defrosted Spinach for Easy Spinach Dip Recipe
Combine the other ingredients using a food processor:
In a food processor, combine the feta, yogurt, sour cream, parsley, grated onion, lemon zest, lemon juice, coriander, and cayenne pepper. Blend until the mixture is very smooth, 1 to 2 minutes.
With the motor running, drizzle in the olive oil and blend until combined, scraping down the sides as needed.
Easy Spinach Dip Ingredients (Minus Spinach) Mixed in a Food Processor
Add the spinach and serve:
Transfer the mixture to a bowl and fold in the chopped spinach. Refrigerate until ready to use.
To serve, taste and add salt, more pepper, or lemon juice if you like. Scrape into a serving bowl and sprinkle with the Aleppo pepper (if using). Serve with crudites, crackers, or pita bread for dipping.
Leftover spinach dip will keep in the refrigerator in an airtight container for up to 5 days.