House Pastrami Recipe

Make brine

In a small heatproof bowl or jar combine apple cider vinegar, water, sugar, kosher salt, and cracked black pepper. Stir until sugar and salt dissolve.

Add the thinly sliced red onion to the brine, pressing the onion down so it's submerged. Let stand at room temperature for at least 20 minutes. For best flavor, refrigerate 1 hour. Leftovers keep refrigerated up to 2 weeks.

In a small bowl whisk together Dijon mustard, mayonnaise, lemon juice, honey (if using), and a pinch of freshly ground black pepper until smooth. Taste and adjust balance; add more lemon for brightness or honey for sweetness.

Place a small dry skillet over medium heat. Add whole mustard seeds and toast, shaking the pan, until they become fragrant and begin to pop lightly, about 1 to 2 minutes. Transfer to a small bowl to stop cooking.

Butter one side of each slice of rye bread evenly with the unsalted butter. This will be the outside for grilling.

Spread about 1 tablespoon of the prepared dijonnaise on the unbuttered side of each slice of bread (the sandwich interior). Reserve remaining dijonnaise for extra if desired.

Layer on one slice of bread (dijonnaise side up): 3 oz (half) of the sliced pastrami evenly, then one slice of Swiss cheese, then half of the pickled red onions (about 1/4 cup). Sprinkle toasted mustard seeds evenly over the onions (about 1/2 tsp). Top with remaining pastrami and pickled onions if you prefer a taller sandwich. Place the other slice of bread on top, buttered side out.

Heat a skillet or griddle over medium-low to medium heat. Place the sandwich in the skillet and cook until the bread is golden brown and the cheese begins to melt, about 3 to 4 minutes. Carefully press down with a spatula or a sandwich press to encourage melting and even contact.

Flip the sandwich and cook the second side until golden and the cheese is fully melted, another 3 to 4 minutes. If the bread browns too quickly before the cheese melts, lower heat and cover the skillet for 1 to 2 minutes to trap heat.

Remove the sandwich to a cutting board and let rest 1 minute. Slice in half on the diagonal and serve immediately with any remaining pickled onions or dijonnaise on the side.