Heat the olive on medium high in a large non-stick skillet. Add the sliced onions and spread them out evenly.
Reduce heat to medium low and sauté until the onions are soft and beginning to brown. About 5-10 minutes.
Add the sugar or maple syrup and a pinch of salt and pepper. Stir to combine.
Add the thyme springs to the skillet and stir again. Let sauté, stirring every few minutes until the onions are nicely caramelized. About 15-25 minutes.
Pour the broth into the skillet and continue to sauté until the broth has been absorbed. Turn off the heat and remove the sprigs of thyme, discarding them.
Preheat the oven to 425 degrees(F).
Mash the vegan butter in a medium sized mixing bowl with a fork. Add the garlic, herbs and a pinch of salt and pepper to the butter. Mix until combined.
Slice your loaf of bread in half and place them on a large baking sheet.
Spread half the garlic butter on one slice of the loaf and then half on the other. Spoon half the onions on top of the garlic butter on one slice and then the remaining onions on the other slice. Spread them out evenly. Divide the cheese evenly and sprinkle over the onions.
Bake for 15-18 minutes or until the top is golden brown and melted.
Let cool for a few minutes and then cut into slices and serve.