I hav a 5 years old baby what is the best way to gain his weight as his weight is just 13kgs

A. Hello mom some kids their metabolism is such. That they don’t gain weight that very easily but are active for their age and eat healthy diet . So some Variation. Is acceptable. You can give them foods such as eggs, dry fruits and nuts , stuff paranthas with potatoes , Panner etc , variety of dals , chana , rajma etc , sago , soya , milk , ghee