Rava sheera and rava kesari are variations of sooji ka halwa. The method of preparation of all the three is almost the same except for a few changes here and there. But in all the three recipes, semolina or sooji or rava is the main ingredient. But one difference i noticed in sooji halwa is that here you are adding sugar syrup to the roasted rava. Also the amount of ghee and water added also differs. You can also add milk while preparing this halwa.