Short, direct answer:

From a Jain dharma point of view, it is not ideal for a Jain to eat food cooked in a non‑veg kitchen or by someone who regularly cooks non‑veg, unless you are sure that:

1. The food itself is strictly Jain (pure vegetarian, no eggs, no meat/fish, ideally no root vegetables etc.).
2. Separate, clean utensils, oil, pan, spoons, chopping boards, etc. are used (no mixing with non‑veg items, grease, or leftover particles).
3. The place where it is cooked is kept clean and free from non‑veg contamination as far as possible.

Why?

• Jain dharma stresses ahimsa (non‑violence) and shuddha ahar (pure food).
• Food cooked in a non‑veg environment usually has traces of himsa (meat particles, oils, broths, same knives/boards, etc.).
• This increases karmic impurity and reduces the spiritual purity of what we eat, even if the dish on your plate is technically “veg”.

So, practically:

• Best: Eat food prepared in a Jain home/kitchen or in a place that follows Jain rules carefully.
• Second‑best (compromise, when no choice):

- Choose the simplest vegetarian items. - Confirm no eggs, meat stock, fish sauce, gelatin, etc. - Prefer freshly cooked food over buffet/leftovers. - Accept this only as a majboori (compulsion), not as a habit or comfort.

Both Śvetāmbara and Digambar traditions emphasise that a śrāvaka/śrāvikā should avoid such food as far as realistically possible. Some may allow it in emergency situations (travel, illness, no alternative), but even then they consider it spiritually “less pure”, not equal to proper Jain food.

For a simple overview of what counts as Jain food and purity in preparation, you can read more here