When the summer sun screams across Mexico’s city streets and sandy beaches, mangonadas come to the rescue. Also called chamangos, they can be made with any combination of mango sorbet, chopped fresh mango or mango purée, and may or may not be spiked, but they’ll always contain the salty, spicy and tangy flavors of Tajín and chamoy. Tajín, a chile-lime salt, is a delicious addition to sweet and savory foods alike. Its sister condiment, chamoy, is traditionally made from fermented fruit, salt…