Preheat oven to 375 degrees.
Place the potatoes on a baking sheet and bake until tender. Let cool completely, then dice and set aside.
Reduce the oven temperature to 350 degrees.
In a saucepan, combine the potatoes, corn, bell pepper, onion and spinach. Add 1 cup of the enchilada sauce and mix well. Place over medium heat, cover tightly and cook until the spinach is wilted, 5-6 minutes.
Remove from heat, season with salt and pepper, set aside.
Pour about 1/2 cup of the remaining enchilada sauce into a 13x9 inch baking dish. The sauce should just cover the bottom.
In a wide frying pan, over medium heat, warm the remaining enchilada sauce.
One at a time, dip each tortilla into the warm sauce, allowing it to warm just enough to be pliable.
Then, place it in the prepared baking dish and spoon about one-twelfth of the potato mixture along its center. Roll it up and arrange it in the dish, seam side down. Repeat with remaining tortillas and filling.
The dish should be tightly packed. Pour any remaining sauce over the enchiladas. Sprinkle with the cheddar cheese. Bake until heated through and the cheese is melted, about 20-25 minutes.