Peel and cut the mango flesh into thin sticks.
Place them in a shallow dish and marinate with lemon juice.
Rinse the beans, trim the ends and cut into 4-5cm pieces. Then slice them lengthwise or crush them in a mortar.
optional: blanch the beans in boiling water for 2-3 minutes, then cool and drain. If you prefer crunchy beans, skip this step.
Chop the garlic cloves, slice the onion, cut the ginger and chili into thin strips.
In a mortar, crush the mustard seeds with the spices and salt
In a large pan over low heat, dry roast the onion and spice mixture. Add the ginger, garlic, and chili. Cook, stirring, until the onion is translucent.
Add the beans to the pan, mix well and cook for a few minutes.
Add the drained mangoes to the pan and simmer for a few minutes.
Turn off the heat, add the vinegar, sesame oil, and the lemon juice from the marinade.
Transfer to screw-top jars or serve immediately hot, or let it cool to accompany rice, poultry, fish, etc.
