Preheat oven to 400°F. Place potatoes in a shallow foil-lined pan; drizzle with 1/2 tablespoon olive oil and toss to coat. Sprinkle lightly with salt and pepper and toss. Bake 40 minutes, until tender and crisped, stirring after 20 minutes. Loosely cover with foil; keep warm in low oven.

Meanwhile, fry bacon until crisp. Drain on paper towels.

Melt butter over medium heat. Stir in flour and cook, stirring, for about 10 minutes until the mixture is golden. Reserve.

Combine shallots and wine in a nonreactive saucepan; boil until reduced to 1/3 cup. Reduce heat to medium. Stir in the flour and half & half or whole milk, simmer and stir in cheese, a little at a time, until melted and mixture is smooth. Taste; season with pepper. If necessary, thin with more half & half or whole milk. Keep warm.

Combine remaining oil, the vinegar and mustard in a large bowl. Whisk until blended. Season lightly with salt and pepper. Add warm potatoes, bacon, endive and arugula; toss to coat.

Ladle fondue into shallow serving bowls and place the salad on top. Serve right away.