Nibblous | dijon chicken stew with potatoes and kale

Ingredients

• 4 teaspoons olive oil
• 2 cups sliced leek
• 4 garlic cloves, minced
• 1/3 cup all-purpose flour (about 1 1/2 ounces)
• 1 pound skinless, boneless chicken thighs, cut into bite-sized pieces
• 1/2 pound skinless, boneless chicken breast, cut into bite-sized pieces
• 1/2 teaspoon salt, divided
• 1/2 teaspoon freshly ground black pepper
• 1 cup dry white wine
• 3 cups chicken broth
• 1 tablespoon all-purpose flour
• 1 1/2 cups water
• 2 tablespoons Dijon mustard
• 2 cups (1/2-inch) cubed peeled white potato (about 1 pound)
• 8 cups loosely packed torn kale (about 5 ounces)
• crushed red pepper (optional)