Combine avocado, lime juice, basil, sea salt, and black pepper in a small bowl. With a fork, mash the ingredients together, keeping the texture slightly chunky.
In a small bowl, mix balsamic vinegar and honey until well combined.
Toast bread slices (optional).
Spread the mashed avocado evenly onto (toasted) bread slices. Top with crumbled feta and tomatoes. Season with additional salt and pepper, if desired. Drizzle with balsamic glaze and serve.