If it cannot be moved
A kitchen in the north-east is the placement the tradition objects to most strongly, because fire is set in the water corner and the most protected part of the plan carries the heaviest load. Where the kitchen cannot move, the remedies are to move the hob itself to the south-east of the room, keep the corner scrupulously clean, and avoid storage against that wall.
What the ఈశాన governs
The north-east — Ishanya — is the most protected corner in the whole mandala. It carries water and belongs to Shiva, and every school agrees on the same instruction: keep it light, clean, open and low. Almost every serious Vastu fault is some version of loading this corner.
Where the రసోఈ belongs
The kitchen is fire, and fire has a corner. Of all the rooms this is the one where the tradition is least divided and most emphatic, which is also why a kitchen in the wrong corner is the fault people most often ask how to fix.