Mix sour cream, lemon zest and juice in a medium bowl. Combine eggs, dill, onion and capers (if using) in another medium bowl. Stir in half of the sour cream mixture.Advertisement
Add trout, celery, parsley, caraway seeds (if using) and pepper to the remaining sour cream mixture.
To assemble sandwiches: Divide the egg mixture among 4 slices of bread. Top with bread, then spread with the trout mixture. Top with the remaining bread. Cut each sandwich in half and serve.
Kitchen Tip: To hard-boil eggs: Place eggs in a single layer in a saucepan; cover with water. Bring to a simmer over medium-high heat. Reduce heat to low and cook at the barest simmer for 10 minutes. Remove from heat, pour out hot water and run a constant stream of cold water over the eggs until completely cooled.
2 starch, 2 1/2 medium-fat meat