Cut the bell pepper into bite-sized pieces and the fennel into strips. Peel and halve the garlic.
Heat the oil in a pan, fry the vegetables with thyme and garlic until al dente. Meanwhile, mix the balsamic vinegar, salt, sugar and pepper in a bowl. As soon as the vegetables are fried, remove the garlic and mix the vegetables into the vinaigrette. Let it steep briefly and serve while it is lukewarm.
Tastes good as a starter with white bread or as an accompaniment to grilled food.