Place the avocado in a medium size bowl and mash roughly with a fork. Add mint and a large squeeze of lemon juice, mash until just combined. Season to taste with salt and freshly ground black pepper.
Toast or grill rye bread until golden. To serve, spoon ¼ of the avocado mixture onto each slice of bread. Top with feta. Serve immediately garnished with extra mint. Tip: try adding some thinly shaved ham, or top with a poached egg.
