My husband’s work, perfected. He has made this caramelized onion and cheese dip at least three times in search of perfection. And he did it on the third attempt. Neighbors who have tried it encourage him to sell it in small tubs but he wants to make it only for family and friends.
Why use a slow cooker? It takes a long time for the onions to soften and caramelize. If you do this on the stovetop, you will need to stir the onions often to make sure they don’t scorch. Who wants to hover over the stove for an hour or longer to cook onions? Softening them in the slow cooker is the smarter choice.

Because onion is naturally watery, expect a pool of liquid to form at the bottom of the cooker. You will need to separate the onion from the liquid. After straining the softened and caramelized onions, save the buttery liquid. It’s so aromatic and flavorul. Use for making gravy or soup. If not using immediately, transfer to a covered container and freeze.

After 12 hours, the onion slices are fully caramelized and they are ready to meet the cream cheese. To make blending easier, cut the cream cheese into small pieces then just stir in. Another 15 minutes of slow cooking will melt the cheese completely.

The onion and cream cheese mixture will be a bit dense so mayo is added to make it fluffier. For color and flavor, chopped parsley is stirred in too.

A little thyme joins the parsley to give the dip a herby taste and aroma. And, finally, a little soy sauce and Worcestershire sauce to round up the flavors. The dip is done at this stage buy, to allow the flavors to fully develop, it needs to sit in the fridge for a few hours.
Ingredients
- 1 ½ kilograms sweet yellow onion peeled and very thinly sliced
- 2 tablespoons butter melted
- ½ teaspoon salt
- ½ teaspoon pepper
- 1 250-gram pack cream cheese
- ½ teaspoon soy sauce (Kikkoman is recommended)
- ½ teaspoon Worcestershire sauce
- ¼ cup mayonnaise Tip: Japanese mayo is tastier and firmer, and it yields better overall results
- 1 tablespoon chopped fresh parsley leaves plus more to garnish
- ½ teaspoon dried thyme or 1 tablespoon chopped fresh thyme
- 2 pinches chili flakes to garnish
Instructions
- Drizzle the melted butter in the slow cooker.
- Add the sliced onion, toss well to coat each piece with butter, then stir in the salt and pepper.
- Set the heat to LOW and cook the onion slices until browned, about 10 to 12 hours, stirring the onions every three hours or so.
- Strain the onion slices well and return to the slow cooker.
- Cut the cream cheese into small cubes and add to the onions.
- Turn on the slow cooker again, still on LOW, and cook the onion slices with the cream cheese for about 15 minutes.
- Turn off the slow cooker and stir the onions and cheese until blended.
- Add the mayo and parsley and stir to combine.
- Stir in the thyme.
- Drizzle in the soy sauce and Worcestershire sauce and stir until the coloring is even.
- Cool the caramelized onion and cheese dip then transfer to a covered container. Chill in the fridge for a couple of hours before serving.