One of my favorite vegetables is swiss chard.  It's beautiful and dependable and provides me with the mass quantities of leafy greens necessary to make foods such as spanikopita (I just call it spinach and feta pie) or quiche.

 I've had excellent success with a variety of swiss chard called Bright Lights.  It has colorful stems that can be white, yellow, pink, orange or red and keeps producing greens for me long after the spinach has gotten too hot and given up for the season, usually around this time of year.