1. In a large, heavy-bottomed saucepan, heat one tablespoon oil over low heat. Add the onions and the brown sugar and let caramelize for about 20 minutes, until the onions are browned, stirring to avoid burning.
2. When onions are almost done, add the ginger and one of the garlic cubes and continue cooking.
3. When the onions are soft and brown, add the sweet chili sauce, teriyaki sauce, and honey. Let the mixture cook for a few minutes until just simmering. Stir in the remaining garlic cube at the end and season lightly with salt and pepper.
4. Add the sesame seeds and stir to combine. Set aside and let cool.