Preheat oven to 400F. Get your ingredients ready and keep them on standby. I chose to grate my potatoes. I recommend trying to do that when youre about to begin to minimize the browning effect. (Be mindful of your knuckles).
Get the onions, garlic, and potatoes in a hot pan with a little oil. Season them. You dont have to cook it too long. Youre really trying to get the remaining liquid out of the potatoes. While youre doing that, get the roux started with the flour and butter. It would be a good idea to warm your milk at this time as well.
When the roux starts looking pretty, add in the milk while stirring. Season it and add a little more than half the cheese. Then add the ham in with the potatoes. Its already cooked, youre bringing it up to temp and letting your seasonings get on it. Add the tomatoes last to prevent overcooking. Turn it off
Move the mix to a baking pan, add the roux evenly over the top. Add the remaining cheese on top. Bake 35 minutes or until cheese is bubbly and browned to your liking.
Top with toasted bread crumbs and green onions. Allow to cool about ten minutes to set up a bit. (Unlike I did, haha).
