Cook the peas with the mint, if using, in a little boiling water. Drain and put into a bowl.
Peel the avocado and cut into strips. Add to the peas and blend together using a hand-held blender or, for a chunkier texture, a potato masher.
Cook's tip: if you are feeding your baby finger foods, you may like to cut the other avocado half into strips and offer them.