How to Make It
Process hummus, lemon juice, half of the avocado slices, and 1/8 teaspoon each of the salt and black pepper in a miniature food processor until smooth, about 30 seconds. Spread bread slices evenly with hummus mixture.
Drizzle zucchini with oil, and sprinkle evenly with oregano and remaining 1/8 teaspoon each salt and black pepper.
Top 1 bread slice with lettuce, zucchini, bell peppers, roasted red pepper, remaining avocado slices, red onion, and tomato slices. Cover with remaining bread slice. Cut sandwich in half, and serve immediately, or wrap sandwich with plastic wrap, and chill until ready to serve, up to 2 days.