Using a hand blender, blend the mango flesh until smooth (Image 1). Strain the mango puree through a fine-mesh sieve to remove any fibers and achieve a silky-smooth texture (Image 2). Add the lemon juice and stir until combined (Image 3). Set aside.
In a separate bowl, beat the cold heavy cream with an electric hand mixer until soft to medium peaks form (Image 4).
Add the mango puree to the whipped cream and gently fold with a spatula until evenly combined (Images 5 and 6). Be careful not to overmix, as you want to keep the mousse light and airy.
Spoon or pour the mango mousse into individual serving glasses. Cover each glass with plastic wrap and refrigerate for at least 1 hour, preferably overnight, for a firmer, chilled texture (Image 7).
Before serving, garnish the chilled mango mousse with fresh mango cubes and mint leaves (Image 8). Enjoy!
Notes
Choose sweet, ripe mangoes. Since this mango mousse has no added sugar, the sweetness of the mangoes makes a big difference. Use fully ripe mangoes with smooth, juicy flesh for the best flavor.
Strain the mango puree. After blending, pass the puree through a fine-mesh sieve to remove any fibers. This extra step helps give your mousse a silky-smooth texture.
Keep the heavy cream cold. Cold heavy cream whips more easily and holds its shape better. I recommend keeping it refrigerated until you're ready to whip it.
Whip the cream to medium peaks. The cream should be thick enough to hold its shape, with peaks that gently bend at the tips. Avoid overwhipping, as the cream can become grainy and difficult to fold into the mango puree.
Fold gently to keep the mousse airy. Use a spatula to gently fold the mango puree into the whipped cream until just combined. Avoid vigorous stirring, which can deflate the cream and make the mousse denser.
Chill before serving. Refrigerate the mango mousse for at least 1 hour, although I prefer leaving it overnight. This allows the mousse to become colder and slightly firmer while keeping its soft, creamy texture.
Add the toppings just before serving. Garnish with fresh mango cubes and mint leaves right before serving to keep them looking fresh and beautiful.