Can Mediterranean food be made without celery?

Often, yes, especially dishes built around grains, pulses, yoghurt, olive oil, lemon, herbs and grilled meat. Celery is more likely to appear in prepared stock, broth, seasoning mixes, sauces and the vegetable base of a stew than as a defining ingredient. That makes the cuisine workable, but not automatically safe: read labels on every packaged ingredient, including stock cubes and ready-made hummus or dressings.

For flavour in a stew, sauce or broth, use onion, garlic, carrot, fennel or a little leek, depending on the dish and what is safe for you. Fennel gives a fresh, faintly aniseed note, while onion and garlic provide the savoury base celery is often there to support. Do not replace celery with celery salt, and check that any stock or seasoning you add contains no celery or celery derivatives.

Hummus, falafel, Greek salad, Greek-style salad, couscous with peas and onions, and the plain couscous dishes are usually the simplest starting points because their flavour comes from visible, recognisable ingredients. Chicken and pork dishes can also work well when they are seasoned and cooked from scratch, but prepared marinades and stock need checking. For a shared meal, make one dressing and one batch of couscous only after confirming every packaged ingredient is suitable.