Philly Cheese Steak Subs recipe - Oh so good!

Philly Steak and Cheese Subs
For this recipe I will use the following ingredients:

• 4 teaspoon vegetable (or olive) oil mixed with 2 teas. of margarine or butter
• 1 lb boneless rib eye steak thinly-sliced (or you can use thinly-sliced chicken instead of beef)
• 1 large green bell pepper, sliced
• 1 large sweet onion, sliced
• 8 ounces white mushrooms, sliced thinly
• 8 slices provolone cheese (my children prefer cheddar cheese)
• 8 sub buns
• Mayonnaise
• Butter (softened)
• Salt and black pepper to season

Preheat oven to 350 degrees. In a skillet on top of the stove, on medium-high heat, heat 2 teas. vegetable oil to hot and add 2 teas. margarine. Add onions to heated skillet and caramelize onions (brown onions), this will take approximately 15 minutes. Add green pepper and mushrooms when the onions are half-way done (around 5 minutes into the onions cooking time). Let this mixture simmer on low heat.

Meanwhile, start another frying pan of 2 teas. vegetable oil. Heat oil to medium-high heat. Add thinly-sliced pieces of rib eye steak to hot oil and cook for about 15 minutes until browned (no longer pink, I like mine well done). While cooking the other ingredients, open your sub buns up and lay them onto a cookie sheet face up and toast them in the oven for about 5 minutes. Take them out of the oven and spread your sub buns on one side with butter and on the other side with mayonnaise. Once the steak and onion mixture are done, spoon equal amounts into each sub bun and top with provolone (or cheddar) cheese. Add salt and pepper to top and bake on 350 degrees for 5-10 minutes, or until cheese is melted. Remove from oven, let stand for 3-5 minutes and serve warm.
Enjoy!