Wrap rind in cheesecloth and tie tightly with a piece of kitchen twine to form a purse; transfer to a small pot. Add milk and cream and bring to a simmer. Simmer over very low heat for about 1 hour, allowing the cheese to infuse the milk mixture. Remove and discard rind, then strain liquid through a fine mesh sieve; set aside.

Preheat the oven to 325°F. Fill a double-boiler half full of water and heat over medium-high heat, bringing to a vigorous simmer. Whisk 1/3 cup of the sugar and salt with egg yolks in a large heat-proof mixing bowl. Place bowl over double-boiler, gradually whisk in the warm milk mixture and cook, whisking constantly to ensure the mixture does not scorch and the eggs don't scramble, for about 20 minutes, or until slightly thickened. Strain through a fine mesh sieve. 

Divide custard between 6 ramekins or custard cups. Arrange ramekins in a baking pan and fill baking pan with enough hot water to reach halfway up the sides of the ramekins. Place pan carefully in the oven and bake 30 minutes. Rotate pan and bake 30 minutes longer. Carefully remove custards from water bath, cover each ramekin with foil or plastic wrap and chill for at least 2 hours, or overnight. 

When ready to serve, remove plastic wrap or foil and sprinkle each custard with 2 teaspoons of the remaining 1/4 cup sugar. Use a hand-held torch to caramelize the sugar, then chill custards for 1 to 2 minutes before serving to allow the sugar to harden.

Chef's Tip: If a hand-held torch in unavailable, caramelize the sugar under the broiler, watching the custards carefully to ensure the sugar doesn't burn.