Cut the onion, the garlic, the spring onions, and the celeriac into small pieces, and the mushrooms in slices. You can cut the oyster into slices with your hands.
Add the olive oil into a pot, the spices and then, the onion and the garlic.
Continue with the mushrooms, the celeriac, and the spring onions.
Sauté for about 10 minutes.
Add the rice and the lettuce cut in large chunks and mix.
Add enough water to cover and let cook over medium heat for about 20-25 minutes.
Turn off the heat and add a bit of fresh dill in the pan.
In your blender or food processor, grind the whole flax seeds and the sesame.
Put this mixture in a bowl with lemon and a bit of the soup, mix with a spoon and add it back in the pan.
Serve in bowls and add lemon juice and fresh dill.