My grandmother used whatever vegetables she had on hand and often mixed them. The water left on the spinach mixes with the olive oil and garlic and makes a sauce. You can add chicken broth too. If it looks dry add a little water with the spinach. Serve as a side with a load of Italian bread to sop up the sauce.
Add olive oil in saute pan, heat on medium heat and add potatoes. Brown until lightly crisp and toasty
Smash garlic and add to oil, season with salt and pepper.
You can use frozen or fresh spinach. If using fresh wash and drain, try to dry as much as possible, if using frozen defrost in microwave and drain. Add spinach with whatever water is left on it and toss, cove pan with lid and simmer until heated through. Season with salt and pepper to taste.