Preheat the oven to 450° and line a baking sheet with parchment paper, folding up the edges to keep keep sauce in.
Whisk together pomegranate juice, Dijon mustard, honey, and pressed garlic. Set aside.
Preheat a cooking pan over medium heat and add olive oil. Add sliced shallots and sauté until browned and caramelized.
Give the sauce another stir and pour it into the pan with onions. Stir slowly and bring to a low simmer. Let is simmer for 4-5 minutes and season with a little salt and pepper. Stir in fresh minced rosemary. Take off heat.
Pat salmon dry with a paper towel and season it with salt and black pepper evenly.
Pour all of the sauce carefully into the prepared baking sheet, in the middle of the parchment paper well.
Place salmon into the baking sheet skin-side. Bake for about 7-8 minutes, take it out of the oven, and carefully flip salmon skin down. (You may need to use a couple of large spatulas.) Spoon some sauce over the top of the salmon.
Bake for 16-18 minutes, until salmon is done. Bake time will depend on the size and thickness of salmon filet.
When salmon is done, carefully transfer it onto a serving dish and pour the remaining sauce from the parchment paper over the top.
Garnish with pomegranate seeds, chopped pecans, and rosemary.