Preheat oven to 350° F.
Melt butter in a medium nonstick skillet over medium-high heat. Add onion and sauté until translucent, about 3 minutes . Add garlic sauté 1 more minute, or until pale golden. Add salmon and stir until heated salt and pepper to taste . Spoon into prepared pie crust and set aside.
Whisk together the eggs, milk, flour, dill, salt and pepper. Pour over salmon and bake for 45 to 50 minutes or until knife inserted near center comes out clean
Let stand 10 minutes before serving.