Peel and chop the onion, garlic, and ginger. Rinse and finely dice the celery and the cabbage.
Add olive oil to a frying pan over a medium flame.
Add the chopped onion, garlic, and ginger and sauté until the onion is translucent - about 10 minutes. Stir often so the onion, ginger, and garlic don't burn.
Add the mustard seeds to the aromatics and sauté for about a minute.
Then add the chopped celery, tuna, turmeric, cumin, paprika, black pepper, and salt, and stir well.
Add in the sesame seeds and sauté for a minute or so
Add the chopped cabbage and stir well. Let this cook (stirring frequently) for about 1-2 minutes.
Take off the heat and stir in the lemon juice.
Enjoy warm as a salad, or use as a dip - it is delicious with celery, pita chips, or even on a baked potato!