Heat olive oil in a large skillet over medium heat.

Add the sliced onions to the skillet and cook, stirring occasionally, until they become caramelized and golden brown, approximately 20-25 minutes.

In a mixing bowl, combine sour cream, softened cream cheese, dried thyme, garlic powder, black pepper, and salt. Stir until well combined.

Add the caramelized onions to the mixing bowl and mix thoroughly with the cream mixture.

Transfer the dip to a serving bowl and refrigerate for at least 1 hour to allow the flavors to meld together.

Serve the French Vegetarian Onion Dip with your choice of dippers such as potato chips, vegetable sticks, or toasted baguette slices.