A creamy, mousse-like frozen treat that doesn't require an ice cream maker. Feel free to substitute peaches for another in-season fruit. The raspberry sauce is also great drizzled over chocolate cake. You can substitute heavy cream for the sour cream and plain full fat greek yogurt for the labneh; I just happened to have these ingredients on hand and I liked the creamy tang of the labneh/sour cream mixture. —rushyama (@rushyama)
Line a 9x5 loaf pan with plastic wrap, leaving a generous overhang on all sides.
In a medium bowl, whip labneh, sour cream, and vanilla bean paste/extract together to firm peaks (it won't increase too much in volume, but it should stiffen). Refrigerate.
Combine egg yolks and 1/3 c sugar in a stainless steel bowl that can rest over a medium sauce pan. Whisk to combine. Bring 1-2 inches of water to a simmer in a medium saucepan. Turn heat to low to maintain simmer. Place bowl with egg yolk mixture on top, ensuring the bottom doesn't touch the simmering water. Whisk constantly until mixture turns thick and pale and leaves a trail when you lift the whisk, 160F on an instant read thermometer. (This took me about 5 minutes.) Take the bowl off the heat and continue whisking until bowl feels neutral to the touch, about 3 minutes. Set aside to cool completely.
In another bowl that will fit in your makeshift double boiler, combine egg whites, remaining 1/3 cup sugar, and salt. Whisk to combine. Bring water in saucepan back to a simmer and place your egg white mixture on top. Whisk constantly until sugar is completely dissolved (about 3 minutes). If you're worried about pasteurization, continue whisking until mixture registers 140F on an instant read thermometer. Take mixture off the heat and, using a hand mixer, whip until stiff peaks and the mixture is cooled to room temperature. Set aside.
Remove labneh mixture from the refrigerator, and gently fold into the cooled egg-yolk mixture in two additions (try not too deflate too much). Fold in your meringue in three additions, again retaining as much air as possible. Gently fold in diced peaches.
Pour mixture into prepared pan, smoothing top with an offset spatula. Fold overhanging plastic wrap over the top to cover and freeze until solid, about 6 hours or overnight.
To serve, remove from freezer and allow to sit at room temperature for 5 minutes to soften slightly. Invert onto cutting board, remove plastic, and slice. Serve with a drizzle of raspberry coulis.
Mix ingredients together and allow to sit at room temperature for about 15 minutes to let berries release juices.
Transfer mixture to a blender or food processor and blend until smooth. Strain and discard solids. Store in the refrigerator until ready to use. Makes about 1 cup.