Add the bacon to a large baking tray and place in the oven. Turn the heat to 400F/200C and cook until the bacon is crisp with the fat rendered out (approx 20-25 minutes, but just be vigilant).
During this, you can prep the sprouts. Just slice off the firm end (stem), then slice in half. Remove and discard any loose or discoloured leaves.
In a small bowl, whisk together the maple syrup, mustard and balsamic vinegar.
Once the bacon is crisp, remove it and set aside, letting any excess fat drip back into the tray. Add enough olive oil to the bacon fat to make roughly 2 tbsp total fat (for example, if you have ½ tbsp bacon fat, add 1½ tbsp oil). Add the sprouts, salt and pepper, then toss to coat.
Flip them all so they're cut-side-down, then roast in the oven for 20-25 minutes, or until very lightly charred and fork-tender. Timings will depend on the size of the sprouts, so just be vigilant.
Dice the bacon and add it to the tray alongside the maple glaze. Give everything a good toss, then pop back in the oven for 2-3 minutes, just until the bacon warms through and the glaze thickens a little.
Serve and enjoy!