Preheat the oven to 190°C (375°F) and lightly grease a 6-well muffin tin with olive oil. Fill a shallow plate with water. Dip one rice paper sheet briefly—no need to wait for it to fully soften—and place it on a clean surface. Cut it into 4 equal quarters, and slightly overlap the pieces to form a smaller circle. This helps the rice paper fit neatly into the muffin wells. Gently press the assembled circle into a muffin cup, folding in any overhanging edges. Repeat with the remaining rice paper.
Assemble the Filling:
Divide the shredded chicken, cherry tomato halves, and sliced leek evenly between the rice paper cups. In a food processor, blend the eggs, milk, spinach, salt, and pepper until smooth. Pour the mixture evenly into the cups and bake for 20–25 minutes, or until the filling is set.
Finish and Serve:
Once baked, remove from the oven and allow the mini quiches to cool slightly before carefully removing them from the tin. The rice paper will be crispy on the outside but softer on the bottom, so handle gently.. Mix the mayonnaise and sriracha in a small bowl, then either spoon or pipe the sauce over the mini quiches. Finish with a sprinkle of sesame seeds and enjoy!