- Bring 1 inch of water to a boil in a large saucepan.
- Put asparagus in a steamer basket, cover and steam until tender-crisp, about 4 minutes.
- Meanwhile, whisk yogurt, mayonnaise, fresh chopped tarragon, lemon juice, water, mustard, salt and pepper( adjust seasoning according to taste) in a small bowl.
- Drizzle the sauce over the asparagus. Serve warm or cold.