Whisk together the flour, baking soda, salt and oats.
In a mixing bowl whisk together the cooled melted butter, granulated sugar, brown sugar and vanilla, then whisk in the egg.
With a heavy duty scraper or mixing spoon, stir in the flour mixture. When fully blended, stir in the nuts, coconut and chocolate chips. Batter will be soft and will need to be chilled, so cover bowl and chill for 2 hours or until firm enough to scoop.
When ready to bake, preheat the oven to 325 degrees F.
Using a tablespoon measure, scoop dough onto parchment lined or unlined (for crisper cookies) baking sheets and shape into neat rounds. Bake for 12-14 minutes or until cookies are golden brown around the edges and slightly pale in the center. .
Sprinkle cookies with sea salt.
Let them cool on the baking sheet, then carefully transfer to a wire rack.
Notes
Oats labeled gluten-free are made in factories free of wheat. Regular oats should be gluten-free, but might contain traces of wheat.