- 1 kg asparagus, trimmed
- 1 tablespoon vegetable oil
- 1 teaspoon butter
- 2 medium leeks, pale green and white parts only, rinsed and finely chopped
- 1 small onion, finely chopped
- 2 cloves garlic, crushed
- 3 tablespoons uncooked long-grain white rice
- grated zest of 1 lemon
- 5 cups (1 1/4 litres) salt-reduced chicken stock
- 1?2 teaspoon salt
- 1?4 teaspoon black pepper
- 1?2 teaspoon dried tarragon
- 3 tablespoons plain yogurt
- Slice the tips from the asparagus; blanch in boiling water for 1 minute and drain.
- Coarsely chop remaining asparagus. Heat oil and butter in a large saucepan over medium heat. Add leeks, onion and garlic; sauté until softened, 5 minutes. Add chopped asparagus. Cook, covered, for 10 minutes.
- Add rice, lemon zest, stock, salt and pepper. Partially cover; simmer for 30 minutes.
- Purée soup in batches in a blender or food processor. Return to pan. Stir in tarragon and the reserved asparagus tips. Simmer for an additional 3 minutes.
- Remove from heat. Stir in yogurt and serve.