In a skillet, combine olive oil and truffle-infused olive oil over medium heat. Allow the fragrant oils to warm up for about 1-2 minutes.

Add the thinly sliced yellow onion to the skillet and sauté until they turn translucent, about 3-4 minutes.

Toss in the sliced baby bella mushrooms and cook until they are soft and slightly caramelized, about 5-7 minutes.

In a mixing bowl, combine the sautéed onions and mushrooms with the crumbed feta cheese, sour cream, and fresh dill. Mix until well blended and creamy.

Season with salt and pepper to taste, giving the dip a final stir.

Transfer the whipped feta dip to a serving dish and serve with crackers or crostini.