Make dry mix by mixing flour, sugar, coconut and chia seeds. Separately mix eggs and milk with whisk, avoid foaming, then drip into dry mix gradually mixing into slurry, followed by vanilla essence. Drizzle in oil and continue to mix into smooth slurry. Finally, add blueberries making sure evenly distributed in slurry and try not to mesh too many blueberries.
Oil muffin moulds or use paper muffin cups, then spoon or pour muffin slurry into all 12 cups, ensuring each cup has fair share of blueberries. Place a piece of walnut, break into 2 if too big, on top of each cup.
Place in middle of fan forced oven that has been preheated to 185C. Set to bake for 20 + 5 min. Check browness and also use skewer to check that muffins are cooked inside.
Remove from oven, cool and serve. Or cool and seal for freezing.