Traditional Granada cooking is built around cured pork and mountain meat. That's the honest starting point. The city is, however, large enough to have modern restaurants that take dietary requirements seriously.
Vegetarian in traditional bars: berenjenas con miel is everywhere and genuinely vegetarian. Gazpacho and salmorejo are plant-based (though salmorejo often comes with a ham garnish — ask for it without). Pan con tomate, olives, cheese, and tortilla española round out the vegetarian tapa staples. Most traditional bars have something; it won't always be labelled.
Vegetarian restaurants: Realejo has the best concentration. Reverso Gastrobar offers dedicated vegetarian and vegan menus alongside the regular menu. The student population means demand exists and restaurateurs respond to it. For a full breakdown of plant-based eating in Granada — cafés, restaurants, and which traditional dishes work without meat — the Granada vegetarian and vegan guide covers the current scene.
Halal food: The Albaicín has halal butchers and restaurants, particularly on and around Calderería Nueva and the streets connecting it to Gran Vía. Moroccan restaurants here generally observe halal standards, though specifics vary by establishment.
Gluten-free: Spanish cuisine leans heavily on bread, flour-thickened sauces, and fried coatings. Many traditional dishes contain gluten in non-obvious ways. Gazpacho, salmorejo, and migas are bread-based by definition. The safest approach in traditional bars is grilled meat, cured ham, olives, and cheese. Dedicated gluten-free menus exist in a growing number of Realejo and centro restaurants.