This recipe is from Cooks Illustrated and it was beloved at a recent potluck I attended. Someone just emailed to ask for the recipe so I thought I'd post it here.
1 lb green beans, trimmed & cut into 1 1/2 inch pieces
1 lb Red Bliss potatoes, scrubbed & cut into 1/2 inch pieces
3 Tbs extra-virgin olive oil
Table salt & ground black pepper
1/4 tsp sugar
2 Tbs red wine vinegar
1 clove garlic (put through garlic press or mince)
1/2 small head radicchio (about 6 oz) washed and cut into 2 inch by 1/4 inch slices
1. Adjust oven rack to lowest position, place large rimmed baking sheet on rack, and heat oven to 500 degrees. Toss beans and potatoes with 2 Tbs oil, 1/2 tsp salt, 1/4 tsp pepper, and sugar in a large bowl. Remove baking sheet from oven and, working quickly, carefully transfer beans and potatoes to sheet and spread in an even layer. (Do not wash bowl.) Roast until vegetables are tender and well-browned on one side, 20 to 25 minutes (do not stir while roasting).
2. Meanwhile, whisk remaining Tbs oil, vinegar, garlic, 1/4 tsp salt, and 1/8 tsp pepper in now-empty bowl.
3. Toss hot vegetables with vinaigrette and cool to room temperature, about 30 minutes. Stir in radicchio, transfer to serving platter, and serve.
[serves 4]