01 -
Combine blueberries, honey, and lemon juice in a small saucepan over medium heat. Cook for 5 to 7 minutes, stirring occasionally, until the berries burst and the liquid thickens to a jam-like consistency. Remove from heat and let cool slightly.
02 -
Let the brie sit at room temperature for 10 minutes, then slice thinly. Remove the rind if desired for a smoother melt.
03 -
Spread softened butter on one side of each bread slice, covering edge to edge.
04 -
Lay 4 slices butter-side down. Layer on the brie, spoon the cooled jam evenly over the cheese, and top with the remaining 4 slices butter-side up.
05 -
Heat a large skillet over medium heat. Cook the sandwiches for 3 to 4 minutes per side until the sourdough is deeply golden and the brie is melted and oozing. Press gently with a spatula to help the cheese spread.
06 -
Transfer to a cutting board and let rest for 1 minute so the filling sets. Slice diagonally and serve warm.