Heat bacon grease over medium heat in a large skillet. Once hot, add in garlic and onions, stirring and cooking 2-3 minutes. Add in chicken broth and 1 cup milk. Heat mixture until just barely boiling.
Add in frozen tortellini. Give it a quick stir and place the lid on the skillet. Set timer to 10 minutes. Pasta will heat and eventually come to a boil.
Meanwhile, give the spinach a few quick chops and cut the sun dried tomatoes into smaller pieces.
Assemble remaining ingredients. Combine 2 TBSP milk and 2 teaspoons of cornstarch, stirring until smooth.
Once timer goes off, remove the lid but keep the heat on medium. Add in milk-cornstarch mixture, stirring to combine. Add in all remaining ingredients except for Parmesan cheese.
The lemon juice might sound odd to you but it adds a nice pop of flavor that I really loved. Don't leave it out!
Give pasta a few stirs. After about a minute or two the spinach will be wilted and the sauce will thicken up.
Serve with Parmesan cheese on top. ENJOY!
