Preparation:

Preheat oven to 425 degrees F. Combine first six ingredients in large mixing bowl. Transfer to loaf pan and cook for 25 to 30 minutes.While meatloaf is cooking, coat a nonstick skillet with cooking spray and add garlic. Sauté for 5 to 7 minutes, mixing occasionally. 
While garlic is cooking, prepare mashed potatoes according to directions (you can substitute skim or low-fat milk for whole milk, if desired). 
Once potatoes are prepared, cover and remove from heat.  Once garlic is golden-brown in color, add spinach to skillet. Sauté with garlic until spinach is fully cooked. Add garlic-spinach mixture to mashed potatoes, mixing thoroughly.  
Remove meatloaf from oven when center is no longer pink. Cut loaf into four equal pieces and arrange each on plate.  Add ¼ of garlic-spinach mashed potatoes to each and serve.