1. In a large skillet over medium-low heat, melt the butter. Add the sliced onions and cook slowly and uncovered for 30-40 minutes. Stir occasionally at first, then more frequently as they begin to color. The goal is to cook them past “soft” until they are a deep, jammy amber brown. Set them aside to cool slightly.

2. While the onions cook, place the cottage cheese in a fine-mesh strainer set over a bowl. Let it drain for at least 20 minutes. Press gently with a spoon a few times to push out as much excess liquid (whey) as possible. Discard the liquid.

3. Preheat your oven to 375°F (190°C). Grease a 9-inch pie dish.

4. In a blender, combine the drained cottage cheese, eggs, and cornstarch. Blend for 45-60 seconds until the mixture is perfectly smooth, frothy, and has no remaining lumps.

5. Pour the blended custard base into a mixing bowl. Stir in the fresh thyme, salt, and pepper. Gently fold in the cooled caramelized onions and ¾ cup of the shredded Gruyère cheese.

6. Pour the mixture into your prepared dish and spread evenly. Sprinkle the remaining ¼ cup of Gruyère on top.

7. Bake for 35-40 minutes. The bake is done when the edges are set, the top is golden brown, and the center has only a very slight wobble (it should not be liquidy). A knife inserted 1 inch from the center should come out clean.

8. Let the bake cool on a wire rack for 10–15 minutes. This step is critical, as the bake will continue to set as it cools, ensuring a firm yet soft slice.