1. Preheat grill to medium-low heat.
2. In a small bowl combine olive oil, lemon zest and black pepper. Cut the avocados in half and remove the pit. Brush the cut side of the avocados and toast with the olive oil mixture.
3. Place the avocado cut side down on the grill along with the bread. Grill the bread on each side for 15 to 30 seconds, just until toasted. Remove from heat and set aside. Let the avocado grill until charred, 2 to 3 minutes. Flip the avocado over and continue to grill for another 1 to 2 minutes.
4. Remove avocado from heat and cut ¼” slices of avocado while still in the skin then with a spoon, carefully remove the slices. Cut the rye bread in half on the diagonal and top with grilled avocado, a drizzle of the remaining olive oil, and a good sprinkle of the Himalayan sea salt. Serve immediately.