Heat 1 tablespoon of olive oil in a large skillet over medium. When the oil is shimmering in the pan, add the onions, stirring to coat with the oil. Let the onions cook for 25 to 30 minutes, stirring frequently. Reduce heat a little bit if onions start to brown on the edges. At the proper heat, the onions should first soften, then turn translucent, and then begin to take on light golden tones evenly throughout the slices, not just on the edges.

When onions are loose and soft like noodles, about 12 minutes in, drizzle the broth and the balsamic vinegar on top, along with a pinch of sugar, mixing well to incorporate. Continue cooking the onions until they darken a bit more and become cohesive, almost jammy. Remove from heat to cool.

Towards the end of the onions' cooking time, fry the bread. Heat a small skillet over medium heat, until drops of water flicked on the surface sizzle away on contact.

Drizzle the oil in zig-zags across one side of the bread. Lay the bread oil side down in the center of the skillet. Press gently on the slice to ensure maximum contact with the pan.

Let the bread toast on the one side for several minutes. Check periodically by carefully lifting up a corner of the bread and examining the underside. You're looking for a nice, golden brown across the surface.

When the first side is ready, drizzle more oil over the second side (the "up" side) and flip the bread. Again, let the bread toast until that side is golden brown. Remove to a plate to cool.

To assemble the fried toast: spread the cheese spread on the cooled fried toast, using as much or as little as you want. Layer the onions on top.

Sprinkle the Gruyere over the onions in a thick layer. Optional: you could place the toast under the broiler for a minute or two to melt the cheese.

Drizzle the chili crisp, if using, over the cheese, and then top with the crispy fried onions. Serve immediately