In a large bowl, mix the buckwheat flour, baking soda, salt, and ground chia or flax seeds until evenly combined.
Preheat the oven to 150°C (fan) or 170°C (no fan), then grease and line a baking tin to prevent sticking.
Heat a pan over medium heat and lightly roast the almonds until fragrant, then set them aside to cool.
Add pumpkin and sunflower seeds to the same pan and toast them gently while stirring until lightly browned.
Roughly chop the almonds and prepare any dried fruit by cutting it into smaller pieces if needed.
In a separate bowl, combine the oil, maple syrup, vinegar or lemon juice, and water, mixing until well blended.
Add the roasted nuts, seeds, and dried fruit to the dry ingredients and mix thoroughly.
Pour the wet ingredients into the dry mixture and stir until everything is fully combined.
Let the batter rest so the chia or flax seeds absorb the liquid and thicken the mixture.
Transfer the batter into the prepared baking tin and sprinkle extra seeds on top if desired.
Bake until the bread is fully set and a skewer inserted into the center comes out clean.
Remove from the oven and allow the bread to cool completely before slicing with a serrated knife.