Add 1/2 tablespoon of hummus to the first layer with cucumber, bell peppers, and tomatoes on top. If I had a hard time getting a vegetable to stay on the sandwich, I'd use the hummus as a "glue."Next, I added the collard greens, avocado, onion, and sprouts on top.
Add 1/2 tablespoon of veganaise to the last layer of bread and add it to the top and press down gently. Add two toothpicks to each side and use a serrated knife to half the sandwich. Repeat this until all sandwiches are assembled.