Caramelized Onions:

Melt the butter in a large saucepan.

Add the sliced onions.

Cook over low heat, tossing occasionally with a spatula, for 1 hour or until onions are soft, sweet, and golden brown.

Tart:

Preheat oven to 400° F / 205° C. Line a half-sheet rimmed baking tray with parchment.

Unroll puff pastry on a silicone baking mat.

Cut a circle, approximately 10 inches in diameter. (I like to trace around a dinner plate.) If desired, save the scraps to make puff pastry twists.

Transfer pastry to prepared tray.

With a rubber spatula or small stepped palette knife, spread the fig jam evenly over the surface of the pastry, allowing a 1-inch border around all edges.

Layer the onions on top of the jam.

Scatter with the goat cheese.

Top with the sliced figs.

Add the lemon slices.

With a pastry brush, brush the beaten egg along the pastry border.

Turn up the edges.

Brush the pastry with more egg wash.

Bake in preheated oven for 25-30 minutes, or until pastry is flaky and deeply golden brown.

Drizzle with the honey and sprinkle with the chopped rosemary.

Slice the tart into wedges. Serve hot.

Wrap leftovers in foil and store in the refrigerator for up to two days. Eat cold, or gently reheat in a 350° F oven for 10 minutes, or until warmed through.