HEAT 2 to 3 inches of water, vinegar and 1 teaspoon salt in large saucepan or deep skillet to boiling. ADJUST heat to keep liquid simmering gently. BREAK eggs, one at a time, into small bowl. HOLD dish close to surface of pan and SLIP egg into water.
COOK eggs until whites are completely set and yolks begin to thicken but are not hard, 3 to 5 minutes. Do not stir. LIFT eggs from water with slotted spoon; DRAIN well on platter lined with paper towels. KEEP warm.
WHISK egg yolks, water, orange juice and lemon juice in a small saucepan until blended. COOK over low heat, whisking constantly, until mixture is foamy and small bubbles appear alongside of pan. WHISK in cut up butter, one piece at a time, until butter is melted and sauce is thickened. REMOVE pan from heat immediately. WHISK in orange zest, remaining 1/8 teaspoon salt and red pepper.
SPREAD muffin halves with remaining 2 tablespoons softened butter. ARRANGE muffin halves on plates and TOP with salmon. PLACE one egg over salmon, TOP with sauce and SPRINKLE with dill.
This recipe is an excellent source of choline, vitamin D, protein and vitamin A, and a good source of folate.