Step 1

Place mushrooms in a food processor. Process until finely chopped. Heat oil in a large frying pan over mediumhigh heat. Add onion. Cook for 5 minutes or until softened. Add mushroom. Cook for 5 minutes or until softened. Add garlic and thyme. Cook for 1 minute or until fragrant. Add lentils, flaxseeds and stock. Bring to the boil. Reduce heat to low. Simmer for 5 minutes or until almost all the stock has evaporated. Transfer to a heatproof bowl. Add mustard and breadcrumbs. Season with salt and pepper. Stir to combine. Set aside for 30 minutes to cool.

Step 2

Preheat oven to 200C/180C fan-forced. Line 2 large baking trays with baking paper.

Step 3

Cut 1 pastry sheet in half to make 2 rectangles. Place ¼ of the mushroom mixture along 1 long edge of each rectangle. Roll up to enclose filling. Repeat with remaining pastry and mushroom mixture. Cut each roll into 4 pieces. Place, seam-side down, on prepared trays. Brush rolls with milk. Sprinkle with seed mixture. Spray with canola oil. Season well with salt and pepper.

Step 4

Bake rolls for 25 to 30 minutes or until pastry is golden and puffed. Set aside for 5 minutes to cool slightly. Serve rolls with tomato sauce.