1Place the barley, measured salt, and water in a medium saucepan with a tightfitting lid. Bring to a boil over high heat, then reduce the heat to low and simmer covered until the barley is tender but still slightly chewy, about 30 to 45 minutes. Drain and set aside to cool.
2Bring a large saucepan of heavily salted water to a boil over high heat. Add the chard and mustard greens and blanch for 1 minute or until wilted and tender. Drain and let cool slightly.
3Place the cooled greens, almonds, vinegar, and garlic in the bowl of a food processor fitted with a blade attachment. With the motor running, add the oil in a steady stream until all of the ingredients are evenly incorporated, about 2 minutes. Scrape down the sides of the bowl, season with salt and pepper, and process until smooth.
4Place the reserved barley in a large bowl, add the pesto, and mix to combine. Season with salt and pepper and serve.