Place the first three ingredients in a medium-sized heatproof bowl. Bring a pot of water to a simmer. (The pot should not be as wide the bowl, as the bowl will need to rest on top of the pot.)
Whip the egg yolk mixture with a thin whisk until very, very light and foamy. Place the bowl over the pot of simmering water (the bottom of the bowl should not touch the water). Continue rapidly whisking the egg mixture until it greatly increases in volume, becomes almost as thick as whipped cream and begins to feel quite warm, not hot. (This will take a few minutes to achieve and you may need to remove the bowl from the heat occasionally to ensure the eggs don’t overheat, over-cook and curdle.) Spoon the sabayon into two - not overly large - martini or other decorative glasses. Serve with strawberries for dipping.