Preheat the oven to 250 degrees F.
Spread the bagel bits out on a baking sheet and toast until dry, 12 to 15 minutes. Allow to cool, and increase the oven temperature to 350 degrees F.
Melt the butter in a small sauce pan over low heat. Add the sesame seeds and garlic and swirl until golden brown, 3 to 5 minutes. Add the chicken broth and cream cheese, increase the heat to medium and bring to a simmer, stirring occasionally to help dissolve the cream cheese.
Place half the bagel bits in a 9- by-13-inch baking dish. Sprinkle half of the red onions and capers over the stale bagel bits. Add the chopped smoked salmon. Cover this mix with the remaining the stale bagel bits and top with the remaining red onion and capers. Add the caper brine for good measure.
Now carefully pour the chicken stock cream-cheese mixture over the bagel bits. Use a rubber spatula to press the mix out evenly. Bake for 15 minutes.
Remove from the oven and allow to cool for 10 minutes before serving.