Smoked Trout Salad Sandwich

Ingredients

• 1 3 oz can smoked trout in canola oil
  
• 2 scallions, both white and green parts, thinly sliced
  
• ¹/₂ teaspoon freshly grated horseradish
  
• 2 tablespoons plain nonfat Greek yogurt or canola oil/reduced fat mayo
  
• 2 tablespoons light sour cream
  
• 1 teaspoon dijon mustard
  
• juice of 1/2 lemon
  
• ¹/₄ teaspoon lemon zest
  
• 1 tablespoon chopped dill
  
• 1 tablespoon chopped parsley
  
• 2 pieces hearty whole-grain bread, such as sourdough, rye or pumpernickel
  
• ¹/₂ cucumber, peeled and thinly sliced into rounds
  
• 1 small tomato, thinly sliced