To a heatproof bowl, add the peas and baking soda tablet and cover with boiling water and soak for 12 hours.

After 12 hours drain and rinse the peas.

Add the peas to a saucepan and fill with water until they are just covered. Do not add salt yet as it will extend the cooking time.

Bring to a simmer/slightly bubbling; do not boil, for 30 minutes uncovered, stirring from time to time until mushy and he water is evaporated. If after 30 minutes they are too watery, continue to cook until the water is evaporated. If they are getting to dry and not mushy yet, add a little water.

As the water evaporates and they thicken, they will start to bubble up and spit. You can turn down the heat accordingly. Note: They will thicken a lot as they cool, so keep this in mind when monitoring the thickness.

When they are at the desired consistency, stir in the salt. Taste and  add more if needed. 

Optional additions to mushy peas: Stir in a little butter for added creaminess. Some chopped fresh mint and a little sugar which is a delicious flavor combination, or a little ground black pepper or malt vinegar for a little tang.