Gather your supplies
Swish your chopped leeks in a bowl of water. All the sand will sink to the bottom and you'll scoop up sand-free leeks.
Scatter on baking sheet, drizzle with olive oil, season with salt and pepper. Roast at 400 degrees for 10-15 minues.
Remove sausage casings. Brown in skillet over medium heat crumbling with spoon as you go.
When leeks soften and tomatoes start to burst they're ready to come out of the oven. Turn the heat down to 325.
Scatter ingredients in greased casserole dish. Pour egg whites to cover and top with cheese. Return to oven until egg sets and cheese browns. 30 minutes or so.