In a microwave/heat-proof large bowl, whisk eggs and sugar together until combined.

Zap butter in a heat proof mug or bowl for 1 minute to melt. Add the lemon juice and zest* along with butter to the egg and sugar mixture and stir until smooth.

Microwave the curd in 1-minute intervals, stirring after each minute has completed**. Microwave the curd for a total of five minutes, and carefully strain the curd into into heat-safe containers (like mason jars or a Pyrex dish). This can be kept in the fridge for upwards of one month or six weeks tops. This is perfect on toast, as a filling in cakes, on cookies, in tarts, etc.!