Mix the rye, water and sourdough starter. Cover and let sit for about 20 hours at room temperature.

After the 20 hours, lightly toast the oats in a dry frying pan. Be careful not to burn. Set aside in a small bowl for now.

Except the oats, mix the remaining ingredients into the rye sourdough mixture. Mix until the dough comes together then remove to a floured surface to knead.

Knead for at least 15-17 minutes. The dough should. Be smooth and elastic.

Fold and knead in the oats in batches. After all oats have been incorporated, knead for 1 more minute.

Form into a ball, cover with plastic wrap and let rise for 3 hours.

After 3 hours it should be noticeably bigger in size.

Remove dough to a floured surface and divide into 8 equal pieces.

Form each piece into round roll.

Dust each roll with rye flour and cover in a baking cloth or tea towel to rise for 1 more hour.

Meanwhile, preheat the oven to 230C/450F. Place a shallow pan on the bottom rack while preheating (you'll add boiling water to this later to create steam).

After 1 hour of rising, arrange the rolls on a baking sheet with the creases at the bottom. Pour some boiling water into the shallow pan in the oven to create steam, the immediately put in the rolls.

Bake for 20 minutes, removing the steam pan after 10 minutes. Let cool on a rack.