1. In a large mixing bowl, whisk the egg. Add the milk, oats, basil, oregano, salt, marjoram, and thyme. Stir to combine. Let the mixture sit for 5–10 minutes to allow the oats and herbs to soften.
2. Meanwhile, preheat the oven to 425°F. Line a large baking sheet with parchment paper or a silicone baking mat.
3. Add the ground beef to the oat mixture. Using clean hands, gently mix until just combined. Avoid overmixing to keep the meatballs tender.
4. Scoop heaping tablespoons of the mixture and roll into balls (about 16 total). Place the meatballs on the prepared baking sheet. Tip: Dip your hands in cold water to help prevent sticking.
5. Bake for 15–20 minutes, or until golden brown and cooked through. The internal temperature should reach 160°F.
6. Remove from the oven and serve warm.

Storage: Refrigerate leftovers in a sealed container and use within 3–4 days. For longer storage, freeze meatballs in a single layer on a baking sheet. Once frozen, transfer to a freezer-safe bag or container and freeze for up to 3 months.