Add carrots; reduce heat, and simmer 5 minutes or until crisp-tender.
Drain; rinse under cold water. Rub carrot peels off with a clean, dry kitchen towel.
Melt butter in a large skillet over medium-high heat; swirl to coat.
Add onion; saut 3 minutes or until slightly tender.
Add carrots, sugar, vinegar, salt, and pepper; cook 2 minutes or until sugar dissolves and carrots are thoroughly heated. Stir in tarragon. Top with pea tendrils.