Set aside an 8-hole muffin tray.
Combine water measure (water should be lukewarm from the tap) and focaccia bread mix in a large bowl and mix well. Remove dough from bowl, wipe bowl clean and grease lightly with first measure of oil. Return dough to bowl, stretch and fold each side of the dough on top of itself, repeating this a few times.
Cover and leave in a warm spot to rise for about 1 hour, until doubled in size. Repeat the folding process and leave to rise again for another hour.
Divide half of the second measure of oil between each cup of the muffin tin. Remove focaccia dough from bowl and divide into equal pieces. The dough should only be big enough to fill half the depth of the muffin tray. Add each piece of dough into the muffin tray, cover and leave to rise for a further 30 minutes.
Preheat oven to 220°C (or 200°C fan bake). When focaccia has risen, drizzle olive oil over the top of each piece of dough, sprinkle over rosemary salt and bake in oven for 15-20 minutes, flipping halfway through, until golden and cooked through.
Cut mini focaccia in half and enjoy with a decent spread of butter.