Cut a piece of parchment paper so that it will cover the pie crust. Prick the crust with a fork, then cover the crust with the parchment paper and fill it with pie weights. Bake 15 minutes and remove the parchment and the pie weights off the crust and let it bake for another 5 minutes.
In a skillet over medium low heat, melt the butter then add the shallots and saute, stirring and cooking until they are softened and lightly browned.
Sprinkle the shallots with 1/2 tsp sugar and continue to cook, stirring occasionally until they are darker browned and caramellized. Remove pan from heat.
Chunk the salmon into bite-sized pieces. Toss in the skillet with the shallots and then scatter the mixture over the bottom of the warm pie crust. Crumble the Boursin over the top.
In a bowl, whisk together the eggs, cream, milk, lemon zest, dill and pepper. Pour evenly over the salmon in the pie plate. Gently top with the bits of sugar snap peas.
Bake the quiche in the middle rack of the oven for 25-30 minutes, until the middle no longer jiggles when you give the pie a gentle shake and the edges begin to colour a bit.
Remove from oven and let sit to cool for about 10 minutes before slicing to serve.