Quick haddock florentine

1) Add the milk, butter and flour to a saucepan over a low heat.
2) Whisk continually until it starts to thicken.
3) Add half of the cheddar to the sauce and season as required (heavy on the black pepper if you are anything like me).
4) Meanwhile saute the haddock fillet skin side down in the olive oil until crisp and turn and cook as desired.
5) Remove the haddock from the pan and put into your dish then add the spinach to the pan until wilted.
6) Top the haddock with the spinach, pour over the sauce, sprinkle over the remaining cheese and place under the grill for a few minutes until golden.