Prep the strawberries. Rinse, hull, and roughly chop half the strawberries. Mash them with a fork until slightly chunky. Slice the remaining berries for topping.
Mix the base. In a jar or container, stir together oats, milk, Greek yogurt, chia seeds, honey or maple syrup, vanilla, and salt until well combined.
Fold in the mashed berries. The mixture will turn light pink and smell like strawberry shortcake.
Taste and adjust sweetness if needed.
Chill overnight. Cover and refrigerate for at least 4 hours, ideally 8–12, to let the oats soften and the chia thicken.
Stir and top. In the morning, give the oats a good stir. If they’re too thick, splash in a bit more milk. Add the sliced strawberries and your favorite toppings.
Serve cold or cool. These are best straight from the fridge, but you can let them sit at room temp for 10 minutes if you prefer less chill.