Using a 10cm circular pastry cutter, cut 8 circles out of the pastry sheet and line 8 small tartlet cases. Prick the base with a fork, sprinkle half of the grated cheese into the bottom of the tartlet cases and place in the fridge until needed.
Cut the potatoes into small cubes and finely chop the garlic, chives, and spring onions.
Heat a pan over medium heat, sauté the bacon, potatoes, and garlic together until they start to brown. Season with salt and pepper.
In a large bowl, mix together the chives, spring onion, yoghurt, eggs, and the rest of the grated cheese. Add the bacon and potatoes and stir through.
Remove the pastry cases from the fridge, place them on a baking tray and fill with the potato and bacon mixture.
Place in the oven and lower the oven temperature to 175°C.Bake for 15 minutes, until golden brown and cooked.
For the side salad: thinly slice the red onion and cut the tomatoes and baby gem lettuce in half.
For the dressing: finely chop the shallot and mix together with the olive oil, mustard, honey, red wine vinegar, and yoghurt.
Serve the tartlets with a side salad of baby gem lettuce leaves, cherry tomatoes, sliced red onion, and dress the salad lightly with the honey-mustard dressing.