Preheat the oven to 160 degrees fan forced (or 180 degrees conventional). Grease and line a 18cm x 28cm rectangular slice tin and set aside.
Place the dates into the Thermomix bowl and chop for 2 seconds, Speed 10. Scrape down the sides of the bowl and repeat.
Add the water and cook for 6 minutes, Reverse, 90 degrees, Speed 3.
Add the bi-carb soda and mix for 2 seconds, Reverse, Speed 2.
Add the honey, oats, chia seeds and LSA and mix on Reverse, Speed 4 until combined (use the spatula to assist). If the slice is a little too dry or wet, simply add more oats or water.
Press the mixture firmly into the slice tin.
Bake for approximately 30 minutes or until slightly golden and firm to the touch.
Allow to cool in the tray.
Drizzle over the dark chocolate.