Preheat oven to 285 degrees Fahrenheit (dish to cook slowly at low temperature)
On top of stove in a small saucepan over medium heat, combine the Bulgar wheat grains in water, add the 3 frozen sausage links, bring to a simmer, and cook about 10 minutes until sausages are soft. Remove the sausages to cool, then chop into very small pieces and set aside. Meanwhile add in the red pepper flakes and crushed garlic to the wheat broth, change heat to low, and simmer until the wheat grains absorb all the liquid. Remove from heat and and hold ready.
While broth is simmering, chop all the vegetables and set aside.
In a large mixing bowl, carefully separate the three large eggs and discard yolks; then add in the whole egg and beat well. Then add to the eggs the mustard, salt, curry powder and fat-free half and half (milk/cream) and mix well until well-blended and somewhat frothy.
Now add in all of the cut vegetables, the diced sausage pieces, and the bulgar wheat (porridge) mixture. Stir everything together.
Pour the entire mixture (about 4 cups total volume) into the greased baking dish and spread evenly to the sides.
Break up the cheese slices and place on the top of the egg mixture as a topping.
Place pan on center rack of oven and bake, uncovered, for 30 to 35 minutes.
Through oven window (if there is one) watch surface of casserole and when the liquid appears to congeal at the sides and the cheese starts to melt and spread and/or brown slightly, insert a toothpick or fork into the center. If it comes out only slightly wet, and the dish has been in the oven for at least half an hour, the food is probably sufficiently cooked through. You will need to find your own comfort level and preference as to the doneness - something after well cooked and before being too dry and/or burned .
Remove pan from oven and allow to cool for a few minutes (about 10?) before serving.
Cut into equal portions and serve warm/hot with a hot fresh bread and salsa or other moist, vegetable-based sauce or topping.
NOTE: If you wish to have softer (more well-done) vegetables, then saute the chopped potato, green pepper, tomato, and onion pieces in a small amount of oil to cook slightly before adding all the vegetables to the egg mixture. You can vary the ingredients and the number of eggs to suit the tastes and nutritional needs of your family members or guests.