How to Make It
Preheat oven to 450°.
Line a baking sheet with parchment paper. Arrange thyme sprigs in a long row on parchment. Place salmon, skin side down, on top of thyme.
Combine mustard, honey, and vinegar in a bowl. Brush mixture evenly over top of salmon. Sprinkle salmon with 2 teaspoons thyme leaves, salt, and pepper. Arrange lemon slices over salmon.
Bake salmon at 450° in center of oven 26 minutes or until desired degree of doneness. Serve hot or at room temperature.