Depends on the severity of dengue fever and your recovery rate along with your digestion abilities. You need a good diet during recovery but it is best to introduce foods gradually so that you are able to digest them properly without causing any harm.
Next Steps
Consult online for personalised diet plan
Health Tips
Drink plenty of water and fluids for better recovery. Soups can be good to begin with. Check for foods that suit you and include them gradually initially in small quantities.