How to Make It
Preheat the oven to 350°.
Add quinoa and water to a small pot and bring to a boil over high heat. Reduce the heat to low and cook, covered for 12 minutes. Remove from the heat and set aside.
Drain the water from the can of salmon into a two-cup measuring cup. Add enough milk to make 1 1/2 cups total liquid.
Melt 3 tablespoons of butter in a medium frying pan. Add the flour and cook, whisking constantly, until the flour is light brown and no longer smells raw. Slowly add the milk-salmon water and whisk till thick and bubbly. Whisk in the cheese then stir in the salmon and peas. Remove from the heat.
Melt the remaining 3 tablespoons of butter in a large frying pan over medium high heat. Add the cubes of bread and cook for 2 minutes, stirring occasionally.
To assemble the casserole, spread 1/4 cup of the salmon cheese sauce on the bottom of an 8-inch round casserole dish and cover with 1 cup of quinoa then 1 cup of cheese sauce. Make two more layers, ending with a layer of the salmon cheese sauce. Top with buttered bread cubes.
Bake the casserole, uncovered, for 30-40 minutes, or until the sides are bubbling and the bread cubes are toasted and crispy.
Remove from the oven and let cool for 5 minutes before serving.