Mix ground chia seeds with ¼ cup water in a small bowl and let sit for 5 minutes until thickened.
Drain and rinse beans well. Dry them completely with a paper towel to avoid excess moisture.
In a food processor, place the oats and walnuts and grind until blended.
Add the beans, onion, garlic, tomato paste, soy, spices and chia mixture to the processor. Blend until everything is incorporated. If the mixture is too sticky, add a little oat flour.
Place the mixture in the refrigerator for 10-15 minutes or in the freezer to make it easier to handle.
Divide the mixture into 6-7 portions (about ⅓ cup each) and form cylinders with your hands. Place them on a tray lined with waxed paper and refrigerate for 20 minutes.
Wrap each sausage in waxed paper and foil, twisting the ends like candy. Steam for 35 minutes.
Preheat a frying pan over medium heat, coat the sausages with a little oil and brown for 7-10 minutes, turning occasionally until crisp.