Step 1

In a 6-qt. stockpot, bring 8 cups water to a boil. Add beans in batches; cook, uncovered, 2-3 minutes or just until crisp-tender. Remove beans and immediately drop into ice water. Drain and pat dry. Toss together beans and radishes.

Step 2

Place pecans, tarragon, cheese, garlic, salt and pepper flakes in a small food processor; pulse until chopped. Add vinegar; process until blended. Continue processing while gradually adding oil in a steady stream. Toss with bean mixture.