Original Recipe from The Link to the Beloved, translated by Charles Perry/A Collection of Medieval and Renaissance Cookbooks Vol. II, David Freidman:

First. Yoghurt is filtered and garlic is put in it.

Modern recipe:

• 1 pint Plain wholemilk yogurt 
• 3 lg. cloves Garlic, mashed to a paste 
• Nigella seed, ground for garnish (optional - see note)

Discard liquid or use in breadmaking. Put drained yogurt in a bowl. Blend in garlic paste, mixing thoroughly. Leave a few hr. to absorb and develop flavor. Serve with flat bread. 

Serves 8.

Notes on the recipe:

Serving idea - mould Sals in a mound in the center of an earthenware plate covered with a large flatbread. Surround with an overlapping layer of marinated or plain sliced cucumbers. Sprinkle top with nigella and mount with a twisted cucumber slice.