In a small saucepan, heat the heavy cream, milk, and vanilla pod and scrapings until bubbling around the edges and steamy. Cover and set aside to steep for 20 minutes.
Place the chocolate in a medium bowl or quart-sized measuring cup and place a fine-mesh strainer over the bowl.
When the dairy has steeped, whisk together the egg yolks, sugar, and salt in a medium bowl until combined. Secure the bowl on a damp cloth. Reheat the cream until bubbling around the edges again, then, whisking constantly, slowly dribble the hot dairy into the yolk mixture until you have added it all. Return the mixture to the pot and cook the custard over medium-low heat, stirring constantly with a heatproof silicone spatula until the custard has thickened to the consistency of heavy cream, 175-180ºF, 3-5 minutes. Immediately pour through the strainer and into the chocolate.
Let sit for a minute or two to melt the chocolate, then gently whisk to combine. Pour the hot custard into 6 small heatproof cups, ramekins, or canning jars. Cover and chill until firm, at least 2-4 hours and up to 3 days.
To serve, whip the cream with the 1 teaspoon sugar until soft peaks form. (Use right away or chill airtight for up to a day or two.) Top each custard with a dollop of whipped cream, a drizzle of olive oil, and a pinch of flaky salt.
Variation: Rosemary Pots De Crème
Omit the vanilla bean, using 2 sprigs fresh rosemary (4 inches long) and steeping until the dairy is as rosemary-flavored as you like, 5-15 minutes. Proceed with the recipe.
Nutritional values are based on one of six servings.