Chop the spinach leaves, put them in a saucepan, add milk. Cook for one minute after boiling. Cool a little, grind in a blender.
Prepare the potatoes for boiling, add salt and bay leaf. Cook for 20 minutes after boiling. Drain the potato broth. Add the spinach mixture and butter to the hot potatoes and turn them into mashed potatoes. Add garlic, cheese.