In a small pot over medium heat, place about 1/2-1 tsp oil. Add the onions and sauté for about 5-10 minutes, until translucent, stirring occasionally.
Add the blueberries, stir well, and allow to cook down for about another 5 minutes or so. Add the balsamic vinegar, rosemary and the sugar, and stir.
Add the spices and continue to simmer for another 5-10 minutes until the mixture thickens. Set aside.
Slice the baguette and drizzle each slice with a little olive oil. Toast either in the oven/toaster oven or in a dry frying pan over medium heat. Place the toasts on the plate, and schmear each one with a dollop of chevre. Dollop a teaspoon of the blueberry compote on top and garnish with a little sprig of rosemary to serve.