In a medium saucepan, heat the heavy cream over medium-low heat until small bubbles form around the edges (approximately 160°F), ensuring it does not reach a full boil.

In a heat-proof mixing bowl, whisk the egg yolks, monk fruit sweetener, and sea salt together until the mixture becomes pale yellow and slightly thick.

Temper the egg yolks by slowly pouring 0.5 cup of the hot cream into the egg mixture while whisking vigorously to stabilize the proteins.

Gradually pour the tempered egg mixture back into the saucepan with the remaining hot cream, whisking constantly to combine.

Place the saucepan over low heat and stir continuously with a silicone spatula, scraping the bottom and sides to prevent scorching.

Continue cooking until the custard reaches an internal temperature of 170°F (77°C) or is thick enough to leave a clear path when a finger is drawn across the back of the coated spoon.

Remove the saucepan from the heat immediately and stir in the vanilla extract.

Strain the custard through a fine-mesh sieve into a clean glass bowl to remove any potential cooked egg solids.

Serve immediately for a warm pouring custard, or press plastic wrap directly onto the surface and refrigerate for at least 2 hours for a chilled, set consistency.