Amba is green mango that has been pickled with fenugreek, turmeric, garlic, and about a hundred other things, depending on the style you buy (in a jar). Indian amba is usually chunky and spicy-more relish than sauce and used like a chutney. The Arabic version is smoother and a little viscous from the fenugreek. Amba came to Israel via Iraq but, like fiery Yemenite schug, amba has become an essentially Israeli condiment, especially on falafel. Sometimes we use amba as a puree. To make it, just put a jar of chunky amba in a blender and puree until smooth. You can buy amba at specialty food stores.