Meanwhile, in a small bowl, combine ¼ cup water (⅓ cup for 4 servings), stock concentrate, a big squeeze of lemon juice, and half the lemon zest; set aside. Heat a medium, dry pan over medium-high heat. Add almonds and cook, stirring, until golden brown, 2-4 minutes. Transfer to a plate. To same pan over medium-high heat, pour in stock mixture. Bring to a boil and cook until slightly thickened, 2-3 minutes. Turn off heat.