Place the strawberries in a medium pot or large saucepan and smush with the bottom of a glass (being careful not to scrape your pan if you're using a non-stick pan).

Add the honey, vanilla and zest, if using, and cook over medium for about 10 minutes. The mixture should have thickened just a little. To make it thicker, combine 1-3 teaspoons of cornstarch with the same amount of water. Use 1 teaspoon to make the sauce slightly thicker and 3 teaspoons to make the sauce quick thick, almost like jam. Pour the cornstarch slurry into the sauce and stir. Simmer for 1 minute and remove the pot from the heat. Do not let simmer longer or the cornstarch will break down, making the sauce runny.

The sauce will thicken more as it cools. Store in the fridge for no longer than 5 days and freeze any leftovers.