Native to South and Central America, seen here in a home garden. Plants have showy, often intensely bright flowers, and rounded, shield-shaped leaves with the petiole in the centre.
I spoke with the gentleman whose garden this was and he told me these were Tropaeolum majus. All parts of the plant are edible and after he gave me kind permission to take some shots, he and I enjoyed some together before we said cheerio!
Tropaeolum majus (garden nasturtium, Indian cress or monks cress) is a flowering plant in the family Tropaeolaceae, originating in the Andes from Bolivia north to Colombia. It is of cultivated, probably hybrid origin, with possible parent species including T. minus, T. moritzianum, T. peltophorum, and T. peregrinum. It is not closely related to the genus Nasturtium (which includes watercress).