Peel and slice the potatoes and place in your baking dish about 1 to 1.5 inches deep. Sprinkle with 1 tablespoon flour. Placed half the ham cubes over the potatoes.
Preheat oven to 300 degrees. Thin the soup in a saucepan with the milk, warming it on your stovetop; then add the three cheeses and stir until well-blended. Add the rosemary, thyme, and pepper and stir more.
Pour half this mixture over the ham and potatoes in your baking dish. Then, top that with remaining flour, ham, and the other half of the soup-cheese mixture.
Cover the dish and bake for about 1 hour, until the potatoes are done – when they are soft and break easily with a fork, they are done. This should feed a big, hungry group; however, if you live alone, you’ll find that it also freezes well in individual portions or makes tasty leftovers from the fridge.