Soak quinoa in cold water for approximately 10 minutes.
In the meantime, preheat oven to 400 F (200 °C).
Wash and finely slice leek from the bottom to the beginning of the rough green part. Discard green dark green part.
Bring 2 cups of mushroom broth to a boil in a large pot. Make sure the lid sits on tight otherwise too much liquid will evaporate.
Heat a pan over medium heat.
Once pan is hot, add 1 Tbsp butter and once melted add leek and reduce heat to medium-low and caramelize leeks (about 20 minutes). Toss often.
Once mushroom stock is boiling, drain and rinse quinoa in sink then add to mushroom stock, wait for liquid to boil again, then reduce heat to simmer and cover. Cook quinoa until all liquid is absorbed (15-20 minutes).
Once oven is preheated, add 2 Tbsp butter to an oven proof dish and place in oven for about 3 minutes for it to melt and slightly brown.
Take dish out of the oven and add haddock filets. Salt and pepper generously and return to oven for 12-15 minutes depending on thickness.
Wash and spin dry baby spinach.
Once quinoa is cooked, remove from heat, add caramelized leek, baby spinach, and creme fraiche and generously salt and pepper, then mix well.
Serve black quinoa risotto in a bowl and top with baked haddock and its browned butter and add another dollop of creme fraiche if desired.