This French onion dip has been my go-to appetizer for casual gatherings and quiet weeknights alike. I first learned to slow-cook onions until they were deeply caramelized during a small dinner party when I wanted something that felt indulgent but still used pantry staples. The long, sweet-savoury flavor of the onions transforms the simple dairy base into something more complex than a store-bought tub and it always disappears quickly from the serving bowl. The texture is creamy, with soft ribbons of onion through every bite, and the balance of tang from Greek yogurt and sour cream with the richness of mayonnaise makes it versatile enough to pair with crunchy chips or slather on a burger.

I discovered the combination of Greek yogurt and sour cream in this dip when I wanted to lighten a classic diner-style recipe without sacrificing creaminess. Using Greek yogurt adds body and a gentle tang, while keeping the mouthfeel rich. Caramelizing the onions slowly is the secret: patience yields deep mahogany color and a sweet, mellow onion flavor that plays beautifully against garlic and fresh chives. I often make a double batch of the caramelized onions and freeze half for fast dips and sandwiches on busy nights. Serve chilled or at room temperature; either way, the flavor opens up after resting.

Ingredients

• Butter and olive oil: You will need 1 tablespoon unsalted butter and 2 tablespoons olive oil. The butter adds depth while the oil prevents burning during the long, low heat caramelization. Use a neutral extra virgin olive oil or a lighter variety for best clarity in flavor.
• Yellow onions: Two large yellow onions, finely chopped, provide a balance of sweetness and savory notes when cooked down. Look for firm onions with dry skins; the larger the onion, the more natural sugars to caramelize.
• Greek yogurt: One cup of plain Greek yogurt (245 g) adds tang and body. I prefer a full-fat Greek yogurt for creaminess; nonfat works if you prefer a lighter dip but expect a less luxurious mouthfeel.
• Sour cream: Half cup (115 g) offers acidity and richness. Choose a regular sour cream for best texture. Low-fat versions thin the final consistency slightly.
• Mayonnaise: Half cup (120 g) of mayonnaise brings silkiness and smooth fat to the base. A good-quality brand makes a noticeable difference; if you prefer egg-free, swap for a vegan mayo but expect a subtle change in flavor.
• Aromatics and seasoning: Three garlic cloves, minced, 2 tablespoons chopped fresh chives, 1 teaspoon kosher salt, and about 1/4 teaspoon freshly cracked black pepper to taste. These bright notes layer into the sweet onion base and finish the dip.

Instructions

Caramelize Onions: Heat 1 tablespoon butter and 2 tablespoons olive oil in a wide sauté pan over low to medium-low heat. Add 2 large finely chopped yellow onions and spread them in an even layer. Cook gently, stirring every few minutes, for about 30 minutes. Use low heat so the onions sweat and release sugars rather than burning. Expect steam at first, then a gradual browning; scrape the fond from the pan now and then to incorporate those caramelized bits. The onions are done when deeply golden to mahogany and sweet to taste. Remove to a bowl to cool. This step can be done a day ahead and refrigerated in an airtight container. Combine the Base: In a mixing bowl whisk together 1 cup plain Greek yogurt, 1/2 cup sour cream, and 1/2 cup mayonnaise until smooth. Stir in 3 minced garlic cloves and 2 tablespoons chopped fresh chives. Add 1 teaspoon kosher salt and 1/4 teaspoon freshly cracked black pepper, then fold in the cooled caramelized onions. Reserve a small pinch of chives and some diced onions for garnish if desired. Tasting and adjusting seasoning is key: if the dip tastes flat, a touch more salt brightens it; add a squeeze of lemon if you want extra lift. Chill and Serve: Transfer the dip to a serving bowl, cover, and refrigerate for at least 30 minutes to let the flavors meld; several hours is even better. The dip firms slightly when chilled, making it perfect for scooping. Before serving, stir gently and scatter the reserved chives and a few caramelized onion ribbons on top for presentation. Serve with kettle chips, pretzel thins, pita triangles, or crisp vegetables.

Storage Tips

Store the dip in an airtight container in the refrigerator for up to 5 days. If you made extra caramelized onions, freeze them flat in a freezer bag in one- or two-ounce portions for easy future use; they will keep well for about 2 months. When reheating frozen onions, thaw in the fridge overnight and warm gently in a skillet to revive their texture before stirring them into the chilled base. To re-serve leftover dip, allow it to come to room temperature for 15 to 20 minutes and stir; this brings out aroma and softens the dip. Avoid leaving the dip at room temperature for more than two hours to maintain food safety.

Ingredient Substitutions

If you need dairy-free options, substitute dairy-based items with equal measures of full-fat coconut yogurt and a dairy-free sour cream alternative; note that coconut will impart a faint coconut flavor. For egg-free preferences, use a vegan mayonnaise made from aquafaba or soy. To reduce fat, swap regular mayonnaise for a light mayo and use low-fat Greek yogurt, but expect a thinner texture and slightly less richness. For a smokier note, stir in 1/2 teaspoon smoked paprika or a teaspoon of caramelized shallots instead of one onion. Always taste as you go because substitutions change both texture and seasoning balance.

Serving Suggestions

This dip pairs beautifully with a salty, crunchy chip like kettle-cooked potato chips or a ridged Ruffles-style chip that can stand up to generous scoops. It also makes a great spread for toasted sandwich buns or a topping for grilled burgers in place of ketchup and mayo. For a lighter option, serve with carrot and celery sticks, radish halves, cucumber slices, or pita triangles. Garnish with extra chives and a drizzle of olive oil or a few extra caramelized onion ribbons for a pretty, appetizing finish.

Cultural Background

French-style onion flavors have long inspired creamy dips in American home cooking, translating the classic French onion soup profile into a cold, spreadable form. The idea of slow-cooked onions blended with a dairy base stems from mid-20th-century American appetizers where convenience met comfort. While not a traditional French preparation, the flavor profile echoes the same slow-cooked onion technique found in many European kitchens, adapted for contemporary snacking and party culture.

Seasonal Adaptations

In cooler months, serve the dip alongside roasted root vegetables or use warmed caramelized onions stirred into warmed sour cream for a cozy winter version. In summer, lighten the dip with extra Greek yogurt and serve chilled with a colorful vegetable platter and crisp white wine. For holiday parties, mix in a tablespoon of Dijon mustard and a splash of Worcestershire sauce to create a bolder, savory holiday spread that complements roasted meats and charcuterie.

Meal Prep Tips

Make caramelized onions in a large batch and portion them into small containers or freezer bags for quick assembly during the week. Combine the yogurt, sour cream, and mayonnaise base in a wide container and add onions just before serving to preserve the creaminess. If packing for lunches, place dip in a small leak-proof container and include sturdy dippers like pretzel crisps or pita wedges. Label containers with the date and use within five days for best quality.

Enjoy sharing this bowl at your next gathering; its ease and layered flavor will likely make it a repeat request at your table. Encourage friends to bring crunchy dippers and you will have a simple, beloved appetizer that feels special without a lot of effort.