Set oven to 200°C/400°F, combination steam setting (if you have variable steam settings, use 50% - if you can’t vary your steam, just set to combination steam and let the oven take care of the humidity). Lightly grease a baking tray or line with parchment paper, then set aside while you make the sausage rolls.
Place the eggs, pecans, onion, soy sauce and cottage cheese into a food processor and process until smooth.
Scrape the processed mixture into a large bowl and add the breadcrumbs and oats. Mix well and leave to sit for 5-10 minutes until it’s the consistency of peanut butter before dividing the mixture into 6 portions.
Cut each of the pastry sheets in half crosswise to form 6 long rectangles. Place a portion of the filling mixture onto each piece and spread it all the way down one of the long sides of the pastry. Brush the other long edges with a little water and roll each piece of pastry up tightly from the mixture side to enclose the filling, with the seam at the bottom.
Cut each roll into 6 pieces for mini sausage rolls or 2 pieces for meal-sized rolls.
Glaze the sausage rolls by brushing a little beaten egg yolk onto each one, and sprinkle with sesame or poppy seeds. Place them onto your prepared tray and bake until the pastry is puffed and the sausage rolls are golden brown, around 18 minutes. Serve hot.