Preheat the oven to 150 degrees.
Bring water to a boil in a pot and add the cauliflower. Lower the heat and let them shimmer until soft.
Meanwhile place cod fillets in an oven safe baking pan. Season with sea salt, avocado or olive oil, and half of the lemon juice on top of the cod.
Bake in the oven until the inner temperature reaches 54-57 degrees Celsius (about 15-20 minutes depending on how thick your fillets are).
Meanwhile drain the caulifower florets.
Add the spincah, lemin juice, lemon zest, garlic powder, sea salt and dijon mustard (if using) to taste and mix using a hand mixer of mash using a fork. Either mash so that you have some bigger pieces left or mix completely smooth.
Place the cauliflower and spinach mash on two plates. Top with the cof fillets, green leafs, pumpkin and sunflower seeds.