Steam or boil diced apples until very tender, about 30 minutes. Drain if necessary and mash or puree until you have your desired consistency. Let cool, then place in a sealed container in the fridge until ready to use.
Meanwhile, place your egg in a small pot and cover with cold water. The water should be about an inch or so higher than the egg. Cover the pot with a lid. Over high heat, bring your egg to a rolling boil.
Remove from heat and let stand for 12 minutes.
Drain water and immediately run cold water over egg until cooled. Rapid cooling helps prevent a green ring from forming around the yolks.
Peel egg and place in a bowl. Mash very well and set aside.
Prepare baby rice cereal according to package directions, mixing until you have your desired consistency.
Combine mashed egg with 1/4 cup (60 mL) apple puree and 2 Tbsp (30 mL) prepared baby rice cereal in a bowl. Mash together well until you have your desired consistency. Add a little breast milk or formula to thin if you like.