Start by removing the stalks and fronds from the fennel bulbs, then peel off any tough outer layers. Cut the bulbs into wedges, ensuring even sizes for consistent cooking.

Place a large frying pan over high heat. Add olive oil and let it warm up before introducing the seasoned fennel wedges. Sauté for 8-10 minutes, stirring occasionally, until they have a nice golden color.

Reduce the heat to medium-low and add in the unsalted butter, balsamic vinegar, and brown sugar. Stir well to combine and coat each wedge evenly.

Allow the fennel to cook for an additional 15-20 minutes, stirring occasionally to promote even caramelization without burning.

Once cooked, remove the skillet from heat and use paper towels to blot any excess liquid. Transfer the caramelised fennel to a serving plate, sprinkle with finely chopped fennel fronds for garnish, and serve warm.