Preheat the grill to 200°C. Line a tray with aluminium foil. Cook the diced pancetta until it's dark brown and crispy.
Saute the crimson grapes in a shallow pan with the verjuice for a a few minutes until the skins start to split. Drain the grapes and reserve the verjuice for the dressing.
To make the dressing, whisk the verjuice with the olive oil and honey and season with salt and pepper.
Arrange the radicchio leaves on a flat plate.
Scatter the sliced fennel, grapes, goat's cheese, walnuts, thyme and crispy pancetta on top of the leaves, then drizzle with the dressing. Serve immediately with crunchy bread on the side.