Peel the mangoes, remove the seeds, and blend the flesh until smooth.
In a bowl, combine the contents of 3 clear, unflavored gelatin envelopes. Slowly pour 1½ cups of boiling water into the bowl while whisking constantly to dissolve the gelatin completely.PRO TIP: Be sure to whisk the mixture as you slowly pour in the water. This step helps evenly mix the gelatin and prevents lumps for a smooth texture without the need for traditional blooming. Add the puréed mangoes and mix until well combined. As an option, you can add up to ¼ cup of granulated sugar for a sweeter taste.
Pour the mixture into a container and refrigerate for about 4 hours until it solidifies. Cover the container completely to prevent the mangoes from oxidizing or turning brown.
Once the mango gelatin is set, prepare the cream gelatin separately. In another bowl, dissolve the contents of 3 clear, unflavored gelatin envelopes in 1½ cups of boiling water, continuously whisking until fully dissolved.
Add the condensed milk and heavy cream. Whisk until thoroughly blended. As an option, you can add up to ¼ cup of granulated sugar for a sweeter taste.
Cut the mango gelatin into small cubes and gently lift them off the bottom using a spatula.
Carefully pour the cream gelatin mixture over the mango cubes. Be sure the mixture is not too warm to avoid melting the jelly cubes.
Rearrange the mango cubes to distribute them evenly within the cream mixture and keep them submerged to prevent them from oxidizing.
Cover the container and refrigerate for about 4 hours or until completely set and chilled.