Pour 1 cup fresh seed or nut milk into a small saucepan, reserving the rest in the blender. Sprinkle gelatin over the surface, and allow it to bloom 1 minute. Heat over medium heat, stirring, for 2 minutes, until steam forms and the gelatin dissolves, but do not allow the water to simmer. Remove the saucepan from the heat, and allow to cool slightly, 10 minutes.
Add it back into the blender with the following additional ingredients: egg yolks, sweetener of choice, the inside scrapings from 1/2 of a whole vanilla bean or the vanilla extract. Blend on medium speed for 30 seconds. Serve warm, or chill, either in individual serving dishes or one larger serving dish.
To chill, allow the custard 3 hours to set up.
Variation 1 — You can substitute 3 cups coconut milk, raw milk or cream for the homemade nut/seed milk. (Omit the water and seeds/nuts from the ingredients if you sub coconut or dairy milk/cream.)
Variation 2 — To make the room temperature or warm custard even thicker, for scooping up wobbly bites on a muffin or cake, add 2 Tablespoons chia seeds, stirring the seeds in quickly and thoroughly. (This is delicious!) Allow the mixture to set up and thicken 10 to 15 full minutes before serving.