Prepare a baking sheet with parchment paper and set it aside.
In a bowl, combine the diced red onions, apricot jam, and chopped pecans.
Slice the Brie in half, placing one half rind-side down in the middle of the baking sheet. Top the first half with half of the apricot and pecan mixture, add the second half of the Brie rind-side up and top with the remaining apricot and pecan mixture.
Place the baguette slices around the Brie, brush them with some olive oil and sprinkle them with a pinch of sea salt.
Bake the Brie for about 10-15 minutes, or until the cheese begins to melt slightly and the baguette slices turn a nice golden brown.
Serve the appetizer immediately right from the baking tray, or carefully transfer the Brie and baguette slices to a serving platter.