Heat a non-stick pan over medium to high heat.
Pour a thin layer of canola oil (or any other frying oil)
Salt the salmon fillets and place them facing down (skin facing up). Don't crowd the pan - you can cook them one after the other.
Let them brown and then turn them on each side, until browned on all sides (except the skin).
When browned on all sides, take them out - they don't need to be cooked on the inside - they will be cooked in the oven.
Mix the olive oil, mustard, and honey in a bowl until homogenous and thick.
Place the salmon fillets in an oven dish and pour the sauce on them - cover all parts of the salmon. Cover the oven dish.
Place the oven dish in an oven preheated to 180°C(360°F) for 25 mins if salmon fillets are still warm from the frying or 30 minutes if they are cool. If the fillets are too dry, next time lower the time in the oven (they should be moist but cooked).