Preheat oven to 200°C and put flour, sugar, salt, baking soda, baking powder, oat meal, linseed, sunflower seeds* and poppy seeds into a bowl.
Mix everything together.
Add the yogurt.
First mix with a (silicone) spatula and continue then to kneed by hand until everything is mixed in.
Transfer dough onto a floured board and kneed just so it does not stick to your hands anymore.
Pat slightly down to form a disc.
Put on a baking sheet lined with parchment paper and cut a cross, almost down to the bottom.
Bake for 35-45 minutes until golden brown and a tooth pick inserted in the middle of the bread comes out clean (a few crumbs attached is fine).
*Please note that if you use sunflower seeds, they will get a greenish/bluish hue after a few hours. It's not harmful at all and does not affect the bread in any way. Sunflower seeds contain chlorogenic acid which reacts with the baking soda. The Nordic Food Lab wrote a really nice article about it, explaining it all. If you are still worried about it, just leave them out or swap for other nuts or seeds.