Drain chickpeas into a colander placed in the sink, then rinse well with cold water until no more foam appears and let chickpeas drain while you cook the onions.

Heat the olive oil in a large heavy frying pan or saute pan, add the onion, turn heat to medium-high and saute onions until they are lightly browned and starting to get crisp, about 6-8 minutes. Stir frequently while the onions cook, and don't let them get too browned or they will be bitter. When onions are lightly browned, stir in the turmeric, cumin, and cayenne pepper and cook 2-3 minutes more, until the spices are fragrant and slightly toasted

Add the drained chickpeas and cook 2-3 minutes more, stirring so the spices and onions are well-distributed in the chickpeas. Then stir in the lemon juice and cook 3-4 minutes more. Turn off heat and season to taste with sea salt

Let the mixture cool, then transfer to a plastic container with a snap-on lid and let salad chill in the refrigerator at least 30 minutes before serving. Serve cold or at room temperature, tasting and adjusting the flavor with more lemon juice and sea salt before serving if desired.