**Preheat the oven**: Preheat your oven to 400°F (200°C). Line a baking sheet or dish with parchment paper or foil for easier cleanup if desired.
**Make the sauce**: In a small bowl, whisk together the Dijon mustard, honey, minced garlic, olive oil, thyme, and a pinch of salt and pepper. Adjust sweetness or salt to taste.
**Season the salmon**: Pat the salmon fillet dry with paper towels and place it on the prepared baking sheet (skin-side down if skin-on). Lightly season with salt and pepper.
**Spread the mustard mixture**: Use a basting brush or spoon to evenly coat the top of the salmon with the Dijon mixture.
**Bake**: Place the salmon in the oven and bake for 12–15 minutes, depending on the thickness of the fillet. The salmon is done when it flakes easily with a fork and reaches an internal temperature of 145°F (63°C).
**Serve**: Transfer the salmon to a serving platter. Garnish with chopped parsley or a squeeze of fresh lemon juice if desired. Serve warm.