4 orange roughy or red snapper fillet (4 ounces each)
1/8 teaspoon each salt and white pepper
2 tablespoons 2% milk
1 egg yolk
In a large nonstick skillet, combine the water, wine or broth, vegetables, lemon juice, peppercorns, bay leaf and 1-1/2 teaspoons tarragon. Bring to a boil. Reduce heat; add fillets and poach, uncovered, until fish is firm and flakes easily with a fork (about 8-10 minutes per inch of fillet thickness). Remove to a warm serving platter.
Strain 1 cup of cooking liquid, place in a saucepan. Add salt and pepper. Bring to a boil; cook until liquid is reduced to about 1/3 cup. Remove from the heat. In a small bowl, beat milk and egg yolk. Stir 1 tablespoon reduced liquid into egg mixture' return all to the pan, stirring constantly. Stir in remaining tarragon. Bring to a gentle boil over low heat; cook and stir for 1 minute or until thickened. Spoon over fish.