Rich Spinach and Caramelized Onion Dip

I’ve been making this spinach and caramelized onion dip for years, and it’s the one recipe that always disappears first at parties. The secret is taking the time to slowly caramelize those onions until they’re sweet and golden, then mixing them with tangy cream cheese and pecorino romano for the perfect balance of flavors. Trust me, once you try this homemade version, you’ll never go back to the store-bought stuff!

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

• Calories: 1150-1300
• Protein: 30-36 g
• Fat: 95-105 g
• Carbohydrates: 40-50 g

Ingredients

For the onions:

• 2 tbsp olive oil
• 2 large onions (thinly sliced into 1/8-inch half-moons)
• 1/2 tsp salt

For the dip:

• 10 oz spinach (thawed and squeezed very dry)
• 8 oz cream cheese (room temperature)
• 1/4 cup mayo
• 1/2 cup pecorino romano (finely grated)
• 3 scallions (finely sliced)
• 1 tbsp fresh parsley (minced)
• 1 tbsp lemon juice
• 1/2 tsp garlic powder
• 1 pinch red pepper flakes

Step 1: Caramelize the Onions

• 2 tbsp olive oil
• 2 large onions
• 1/2 tsp salt

Heat olive oil in a large skillet over medium-low heat.

Add the thinly sliced onions and salt, then stir occasionally for 25-30 minutes until the onions turn deep golden brown and develop a rich, sweet flavor.

This slow cooking process breaks down the onions' natural sugars, creating the sweet caramelized base that defines this dip.

While the onions cook, you can prepare the other ingredients.

Step 2: Prepare the Spinach and Dry Ingredients

• 10 oz spinach

If using frozen spinach, place it in a fine-mesh strainer and let it thaw completely, then squeeze out as much moisture as possible using your hands or by wrapping it in a clean kitchen towel and pressing firmly.

Dry spinach is crucial here—excess water will make the dip watery.

Once prepared, set the spinach aside and preheat your oven to 350°F, lightly oiling a 9x13 inch baking dish or similar size.

Step 3: Build the Dip Base

• 8 oz cream cheese
• 1/4 cup mayo
• 1/2 cup pecorino romano
• 1 tbsp fresh parsley
• 1 tbsp lemon juice
• 1/2 tsp garlic powder
• 1 pinch red pepper flakes

In a medium bowl, combine the room-temperature cream cheese, mayo, finely grated pecorino romano, minced fresh parsley, lemon juice, garlic powder, and red pepper flakes.

Mix until smooth and well combined.

I like to use room-temperature cream cheese here because it blends easily without lumps—if yours is cold, let it sit on the counter for 15 minutes first.

This mixture creates a creamy, flavorful foundation for the dip.

Step 4: Combine All Components

• caramelized onions from Step 1
• prepared spinach from Step 2
• cream cheese mixture from Step 3

Fold the caramelized onions from Step 1 and the prepared spinach from Step 2 into the cream cheese mixture from Step 3, stirring gently until everything is evenly distributed.

Be careful not to overmix—you want to maintain a slightly chunky texture with visible onion pieces.

Transfer the entire mixture into your prepared baking dish, spreading it into an even layer.

Step 5: Bake and Finish

Bake the dip for 15-20 minutes at 350°F until the edges are lightly golden and the dip is heated through and just beginning to bubble around the edges.

For the best texture, I pull it out when it's warm but still has a little give in the center—overbaking can make it dry.

Remove from the oven and let it cool for 2-3 minutes before serving with crackers, toasted bread, or fresh vegetables.

Rich Spinach and Caramelized Onion Dip

Delicious Rich Spinach and Caramelized Onion Dip recipe with step-by-step instructions.

Print Recipe Pin Recipe

Prep Time 15 minutes mins

Cook Time 25 minutes mins

Total Time 42 minutes mins

Servings: 2.5 cups of dip

Calories: 1225

Ingredients Method

Ingredients

  

For the onions

• 2 tbsp olive oil
• 2 large onions (thinly sliced into 1/8-inch half-moons)
• 1/2 tsp salt

For the dip

• 10 oz spinach (thawed and squeezed very dry)
• 8 oz cream cheese (room temperature)
• 1/4 cup mayo
• 1/2 cup pecorino romano (finely grated)
• 3 scallions (finely sliced)
• 1 tbsp fresh parsley (minced)
• 1 tbsp lemon juice
• 1/2 tsp garlic powder
• 1 pinch red pepper flakes

Method

 

1. Heat olive oil in a large skillet over medium-low heat. Add the thinly sliced onions and salt, then stir occasionally for 25-30 minutes until the onions turn deep golden brown and develop a rich, sweet flavor. This slow cooking process breaks down the onions' natural sugars, creating the sweet caramelized base that defines this dip. While the onions cook, you can prepare the other ingredients.
2. If using frozen spinach, place it in a fine-mesh strainer and let it thaw completely, then squeeze out as much moisture as possible using your hands or by wrapping it in a clean kitchen towel and pressing firmly. Dry spinach is crucial here—excess water will make the dip watery. Once prepared, set the spinach aside and preheat your oven to 350°F, lightly oiling a 9x13 inch baking dish or similar size.
3. In a medium bowl, combine the room-temperature cream cheese, mayo, finely grated pecorino romano, minced fresh parsley, lemon juice, garlic powder, and red pepper flakes. Mix until smooth and well combined. I like to use room-temperature cream cheese here because it blends easily without lumps—if yours is cold, let it sit on the counter for 15 minutes first. This mixture creates a creamy, flavorful foundation for the dip.
4. Fold the caramelized onions from Step 1 and the prepared spinach from Step 2 into the cream cheese mixture from Step 3, stirring gently until everything is evenly distributed. Be careful not to overmix—you want to maintain a slightly chunky texture with visible onion pieces. Transfer the entire mixture into your prepared baking dish, spreading it into an even layer.
5. Bake the dip for 15-20 minutes at 350°F until the edges are lightly golden and the dip is heated through and just beginning to bubble around the edges. For the best texture, I pull it out when it's warm but still has a little give in the center—overbaking can make it dry. Remove from the oven and let it cool for 2-3 minutes before serving with crackers, toasted bread, or fresh vegetables.