Peel, cook, and mash the potatoes.
While the potatoes are cooking, prepare the other ingredients. Tear or cut the spinach into smaller pieces.
In a saucepan over medium heat add the butter, garlic and herbs. Cook until the butter is melted, and the garlic is softened. This will release the flavors of the garlic and herbs.
Reduce the heat to low. Add in the milk. Stir. Stir regularly to prevent scorching. Heat until the milk mixture is heated. It does not need to boil. Just be heated up. Once the milk mixture is heated add the spinach. Stir again until the spinach is wilted.
Remove from heat. Add in the mashed potatoes. Stir until it is all mixed. You may want to add addition al milk if you want thinner mashed potatoes.
Put into your serving bowl and serve.