We fell in love with Pocky sticks during a trip to Japan, where we had these little sweet-salty treats on a daily basis. It seemed a good idea to us to scale them up a bit, and it was in fact a great idea—this way one is enough.
Place the flour, salt, sugar, and ground fennel seeds in a mixing bowl, add the cold, diced butter and rub to a crumb consistency (you can do this by hand or in a mixer with a paddle attachment). Start mixing in the water little by little until you have a tight dough that comes together in a ball. If necessary, add another couple of drops of water, but not too much as this dough should be quite firm. Wrap in cling film and place in the fridge to rest for at least 1 hour and up to 48 hours.
Very lightly dust your work surface with flour and roll the dough into a 10-inch x 14-inch rectangle. Place on a tray and return to the fridge to chill and set for a minimum of 10 minutes. Preheat the oven to 375° F/350° F convection and line a baking sheet with baking parchment.
Cut the chilled dough into 10-inch-long sticks, each just under 1/2-inch wide, and lift carefully onto the lined baking sheet. Allow just a little space between each one so they don't stick to each other when baking. You should end up with about 30 to 35 sticks. Bake for 10 minutes, then turn the tray around and leave for another 5 to 6 minutes until the sticks are golden. Allow to cool on the tray.
While they are cooling, melt 250 grams of the chocolate over boiling water or in the microwave. When it is fully melted, add the remaining 50 grams of chocolate and stir until it melts in too, then stir in the teaspoon of oil.
Transfer the melted chocolate to a tall, dry glass. Dip the sticks in one at a time, coating them about halfway up their length, then pull out, shake off any excess chocolate and lay back on the tray to set. Once you have dipped a few, sprinkle with some sea salt so that it sticks to the setting chocolate. Keep dipping and sprinkling until you have coated them all. Set the tray in the fridge for 10 to 15 minutes, just to harden the chocolate fully, and then store at room temperature in an airtight container. These keep well for a few days.