To prepare the alginate bath: In a bowl, whisk sodium alginate into 500ml of water until fully dissolved. Let it rest for a few minutes to remove any air bubbles. This is your setting bath.

To prepare the yogurt mixture: In a separate bowl, whisk Greek yogurt with calcium lactate until completely smooth. If using dried lavender, steep it in a small amount of hot water (about 10ml) for 2 minutes, then strain and add the lavender-infused water to the yogurt mixture. Add honey and lemon zest. Mix well.

To make the pistachio-oat crumble: In a small bowl, combine shelled pistachios, rolled oats, and a drizzle of honey. Toss to coat. Lightly toast in a dry pan over medium heat for 2-3 minutes until fragrant and slightly crispy, stirring constantly. Be careful not to burn.

To create the yogurt spheres (spherification): Using a dropper or syringe, carefully drop small amounts of the yogurt mixture into the sodium alginate bath from a height of about 5 cm. Let the spheres set for 1-2 minutes, then gently remove them with a slotted spoon. Rinse the spheres carefully in a bowl of clean water to remove excess alginate, then transfer to a separate bowl.

To assemble: Artfully arrange fresh mixed berries on plates. Carefully place the lavender-infused Greek yogurt spheres among the berries. Sprinkle generously with the toasted pistachio-oat crumble. Serve immediately for optimal texture.