In a medium pot over medium heat, cook strawberries, sugar, and lemon juice, smashing with a wooden spoon, until strawberries are broken down, 8 to 10 minutes. Transfer to a medium bowl. Let cool to room temperature, then refrigerate until ready to use.

Make Ahead: Strawberry sauce can be made up to 3 days ahead. Keep refrigerated.

In the large bowl of a stand mixer fitted with the whisk attachment, beat cream on medium speed until stiff peaks form. Transfer to a medium bowl and refrigerate until ready to use.

Into a medium pot, pour enough water to come about one-third up the sides and bring to a simmer over medium-low heat. In a medium heatproof bowl, combine eggs and sugar. Place bowl over pot, making sure water doesn’t touch bowl. Cook, whisking constantly, until smooth and an instant-read thermometer registers 165°, about 5 minutes. Transfer mixture to bowl of stand mixer.

Beat on medium speed with whisk attachment until lightened in color and holds its shape for a few seconds before melting into itself, and sides of bowl are no longer warm to the touch, 5 to 10 minutes.

Reserve ¼ cup strawberry sauce for topping; refrigerate until ready to use. Gently fold remaining strawberry sauce into reserved whipped cream.

Add about one-quarter of whipped cream mixture to egg mixture and gently fold to combine. Fold in remaining whipped cream until just combined.

Line a 9" x 5" loaf pan with plastic wrap, leaving a large overhang on all sides. Pour mixture into prepared pan and smooth top. Fold plastic wrap overhang over to cover top completely. Freeze until solid, at least 6 hours or up to 1 week.

When ready to serve, unwrap top of semifreddo. Flip upside down onto a platter and remove loaf pan and plastic wrap.

Top with reserved strawberry sauce and serve immediately.