Chop the onions, garlic, bell pepper and carrots. Set aside.
In a heavy skillet, using the flour and oil make a roux. Stir continuously and do not walk away!
Once the roux is sufficiently brown, add the chopped veggies. Cook about 4 minutes.
Add the water and bouillon. Stir in the peas and corn. Simmer until the gravy is the desired consistency.
In a second heavy skillet, brown the meat. Drain off any fat. Add enough gravy and veggies to create a moist but not soupy meat mix.
Spread this into a greased 9 x 13 pan.
To the mashed potatoes, add 3/4 cup of grated cheese and spread on top of the meat mixture.
Add the remaining grated cheese on top.
Bake at 350 til hot and until cheese is melted.
NOTE: If your ingredients are not already hot, pour the meat mix, top with the potatoes, cover with foil and bake for about 30 minutes. Remove foil, add cheese to the top and bake til cheese is melted.