Preheat oven to 375 degrees Fahrenheit. Spray a baking sheet with cooking spray.

Lightly rinse salmon, pat it dry, and place on the baking sheet, skin side down. (If you prefer, remove the skin before cooking.)

In a small bowl, mix the mustard, dill, oil, lemon juice, and honey.

Place pistachios in a zip-top bag and seal securely. Use the bottom of a jar to crush them until they resemble breadcrumbs.

Lightly brush salmon with the mustard mixture and cover with pistachios. Season with salt and pepper, if using.

Bake 20 minutes (for fairly well-done salmon).