In a medium-size skillet melt butter. Add the onion, garlic salt, pepper and red pepper flakes. Cook over medium-high heat for 2-3 minutes or until softened and beginning to brown.
Add the spinach. Cook until wilted and liquid is released. Remove from the heat and add cream cheese and ½ cup shredded Parmesan cheese. Mix until fully combined. Transfer to an airtight container and chill until firm.
To prepare: Preheat the oven to 375°F. Spray a large rimmed baking sheet or a broiler pan with cooking spray. Set aside.
Butterfly the pork loin. Use the flat side of a meat mallet to pound to ½-inch thickness into approximately a 12 x 8-inch rectangle. Size may vary depending on weight. Season on all sides with seasoned salt.
Spread evenly over the pork loin leaving 1-inch border. Roll starting from widest edge ending seam side down. Center on the pan.
Cut bacon slices to just long enough to tuck under the pork loin to secure. Repeat, slightly overlapping until entire pork loin is covered.
Arrange vegetables around the pork loin or roast on a separate pan. Spray liberally with cooking spray or lightly drizzle with olive oil.
Season vegetables to your taste with garlic or seasoned salt. Sprinkle with 2 Tbsp grated Parmesan cheese..
Place into the oven and bake for 50-60 minutes or until a meat thermometer inserted into the thickest portion of the pork resisters 145°F. (Time may vary depending in thickness of pork loin)
Rest on counter for 10 minutes then slice into desired size pieces. Serve with vegetables on the side.
I've included vegetables in this recipe as an option. You may omit vegetables, if desired.