Spinach Salad with Mango Vinaigrette and Cashews Recipe

Ingredients

• ½ small red onion, thinly sliced
• 1½ teaspoons kosher salt
• 2 tablespoons unsalted butter
• 1 cup roughly chopped raw cashews
• 3 tablespoons mango chutney
• 2 tablespoons grapeseed or canola oil
• Freshly ground black pepper
• 1 lime, halved
• 6 cups baby spinach
• 2 ripe mangos, peeled, pitted and chopped into ¼-inch cubes