You can change the spices to create different flavor profiles. The spices in this recipe are for a breakfast-type sausage.
Combine red lentils and vegetable stock in saucepan and bring to a boil. Reduce heat to medium low and simmer, uncovered, for approximately 20 minutes, or until lentils are very soft. Stir occasionally to prevent sticking. When cooked, removed the lentils from the heat and stir in the soy sauce and vegetable oil.
While lentils are cooking, combine the vital wheat gluten with the dehydrated onions, garlic powder, sage, fennel, mustard powder, allspice (if using) and salt and pepper. Stir until well mixed.
Add cooked red lentils, oatmeal and 2/3 cup / 160 ml vegetable stock to the vital gluten. Stir until well blended, then knead for a few strokes until the mixture is smooth.
Bring a large pot of water to a boil on the stove. While it is heating, make your sausages by dividing the dough into 8 equal pieces. Cut 8 pieces of aluminum foil for wrapping the sausages. Brush each piece with oil to coat lightly. This will prevent any sticking during cooking.
Roll each piece of dough into a sausage like shape about 6 inches / 15 cm long. The mixture will expand during cooking, so don't make them too thick. Place each sausage on a piece of aluminum foil and roll to cover. Twist the ends of the rolls firmly. When all of the sausages are completed, place in the boiling water, and reduce heat to a medium. Make sure all sausages are covered with water. Cover and simmer the sausages for 40 minutes. The aluminum foil may discolor during the cooking time, but this is only the outside layer in contact with the water. It will not affect the sausages.
Remove pan from the heat, and remove the sausages with thongs. Carefully untwist the ends and remove the sausages from the aluminum foil. Cool in the fridge for several hours before using.
To make sausages for grilling, make the rolls of sausage thinner. You can divide the dough into 10 -12 pieces instead of 8.