1. **Compote:** Combine pitted cherries, brown sugar, orange zest, and juice in a saucepan. Simmer 5-8 minutes until fruit softens. Stir in cornstarch slurry and cook 1 minute until thickened. Transfer to a bowl and chill completely.

2. **Melt:** Melt chocolate in a heatproof bowl over simmering water (or microwave). Set aside to cool to room temperature.

3. **Whip Cream:** Whisk heavy cream to soft peaks. Set aside.

4. **Whip Eggs:** In a clean bowl, whisk egg whites with salt until foamy. Gradually add caster sugar and whisk to stiff peaks.

5. **Combine:** Stir egg yolks into the slightly cooled chocolate. Gently fold this chocolate mixture into the whipped cream. Finally, gently fold in the egg whites in two batches until no white streaks remain.

6. **Assemble:** Spoon a layer of mousse into glasses. Top with chilled cherry compote. Add a final layer of mousse.

7. **Set:** Refrigerate for at least 2 hours before serving. Garnish with fresh cherries.