Lemon juice and bicarbonate are the two best odour neutralisers, first give the inside of the oven a deep clean with bicarb solution until it's cleaned of any stains.
Put a good couple of tablespoons of lemon juice in a mug and add water to ¾ full, place in the microwave and turn on until the water is just boiling. Leave for 10 minutes and smells will go away.
You could also put a small dish of bicarb in the microwave and leave it uncovered with the door closed overnight, and that will absorb smells.