Preheat oven to 400°F (200°C). Toast bread slice brushed with olive oil until golden brown, about 2 minutes. Take out of the oven and cool completely. Alternatively, you can use your toaster.
Combine cream cheese and chives in a small bowl. Season with pepper to taste.
Spread herb cream cheese mixture onto cooled bread slice leaving a 1/2-inch crust around the edges.
Top with sliced heirloom tomatoes and a sprinkle of coarse salt (optional), pepper and chives. Slice and serve immediately with a drizzle olive oil, if desired.