Add the sliced strawberries, sugar, 2 tablespoons of lemon juice, and dash of salt, to a 2 quart sauce pot.

Heat the mixture over medium high heat and cook for about 5-6 minutes until enough juice has been released to partially submerge the strawberries. The sugar should be dissolved and the liquid around the berries should be boiling.

Reduce the temperature to medium heat and let the berries simmer for 10 minutes, to soften. Stir occasionally. Once softened, use a potato masher or a fork to mash the berries until no big chunks remain.

Continue cooking the jam for 30-35 more minutes, stirring often.

The jam is done when the bubbles have slowed and turned thick and syrupy, the mixture will have reduced and will look like it's "breathing" when it simmers.

Remove the pot from the heat. Stir in the lemon zest and more lemon juice to taste. Allow the jam to cool to room temperature before transferring to a jar and storing in the fridge. The jam will thicken as it cools.