Sardine Sandwich with Horseradish Cream & Pickled Red Onion - SippitySup

Ingredients

• ¼ cup rice-wine vinegar
• 1 teaspoon sugar
• 1 teaspoon black peppercorns
• ½ small onion, thinly sliced
• 2 tablespoons mayonnaise
• 1 tablespoon prepared horseradish
• ½ teaspoon fresh lemon juice
• 2 slices pumpernickle bread, toasted
• 2 leaves red lettuce
• 4 ounces canned sardines packed in oil, drained plus 2 tsp reserved oil
• 1 roasted red bell pepper, cut into thin strips
• 1 pinch each kosher salt and black pepper