It’s the Midwest party snack that's earned a devoted following—one cocktail rye slice at a time.Credit: Grant Webster / Food Styling: Emily Nienhaus,Growing up, my grandmother had a small repertoire of party snacks she'd set out during happy hour when the whole family was around. Cheesy olive bites. Shrimp cocktail. Spiced nuts. Cheese puffs. Nothing too fussy or done-up. But always arranged on a pretty tray or in an elegant glass bowl. Nanette …