Whisk almond milk with chia seeds and optional sweetener in a large bowl. Let sit for 5-10 minutes to allow the chia seeds to begin to puff, and then whisk one more time to loosen clumps.
Cover and refrigerate for at least two hours. For optimal results, refrigerate overnight.
Whisk chia pudding well before serving. Top with your favorite ingredients. Store your leftovers in an air-tight container in the refrigerator for up to 5 days.