Hold the bread. This upgrade to your lunch sandwich featuring a veggie-packed flatbread and buttery salmon is guaranteed to do away with #saddesklunch. Assemble just before serving. Instead of mustard, you can add a smear of cream cheese or labneh. And rainbow trout or Arctic char are good swaps for salmon.
Per serving:
Preheat oven to 400 F (200 C). Line rimmed baking sheet with parchment paper and set aside.
In food processor, pulse almonds until very finely chopped. Add pumpkin seeds and sunflower seeds; pulse until coarsely chopped. Transfer mixture to large bowl. Place carrots in food processor; process until very finely chopped. Add carrots, garlic, thyme, cumin, black pepper, salt, eggs, and egg whites to bowl and mix well.
Press carrot mixture in 1/2 in (1.25 cm) thick rectangle layer onto prepared baking sheet. Bake for 25 minutes, or until flatbread is firm and darkened around edges. Cool in pan for at least 5 minutes before slicing into 8 to 10 pieces.
Reduce oven temperature to 325 F (160 C). Line baking sheet with clean parchment paper. Place salmon on sheet, skin side down, and season with salt and pepper; bake until barely cooked through in the middle, about 15 minutes. Let rest for 5 minutes before breaking flesh into large chunks.
Spread mustard on carrot bread slices. Top with arugula, salmon, and roasted red pepper. Squeeze lemon juice overtop.