Preheat your oven to 375°F (190°C).

In a large skillet, heat the olive oil over medium heat. Add the garlic, bell peppers, zucchini, and mushrooms; sauté until tender, about 5-7 minutes. Add spinach and cook until wilted, seasoning with salt and pepper.

Lay out the pork slices on a clean cutting board. Place a generous spoonful of the sautéed veggie mix at one end of each slice, then roll it up tightly and secure with a toothpick or a piece of kitchen twine.

Place the rolls seam-side down in a greased baking dish. Bake in the preheated oven for about 25-30 minutes, or until the pork is no longer pink and the internal temperature reaches 145°F (63°C).

Remove from the oven and let them rest for a few minutes before carefully removing toothpicks or twine. Slice open and serve!