Prepare the fruit and vegetable purée

• Peel the banana and chop the strawberries, zucchini and carrot.
• Scoop out the avocado flesh.
• Blend all the fruit and vegetables together until smooth, keeping at least half of the mix as fruit so it stays palatable.

Make the batter

• Mix the purée with the oat flour and the egg (or a flax egg made from ground flaxseed and water) until you get a thick batter.

Fill the piping bag

• Transfer the batter to a piping bag, or a ziploc bag with the tip snipped off.

Pipe the puffs

• Pipe the batter onto a parchment-lined baking sheet into little circles or whatever shape you like.

Bake the puffs

• Bake until the puffs are dry and lightly golden, without letting them get too crunchy so they still dissolve easily in a baby's mouth.

Cool and check the texture

• Let the puffs cool, then taste one yourself: they should be fairly bland with a bit of sweetness.