Preheat the oven to 400oF (204oC) and line a baking sheet with parchment paper. Add sea salt to the salmon and bake for 10 to 12 minutes or until cooked through and flaky. Once cooled, flake into pieces with a fork.
In the mason jar, whisk together the extra virgin olive oil, lemon juice, mustard and remaining sea salt. Add the cucumber, salmon and the romaine. Seal with a lid.
When ready to eat, shake well and dump into a bowl. Enjoy!