Preheat a large pot over medium heat and add vegetable oil.
Slice onions and peppers thin and add them to the pot. Mix, cover and cook until they start to soften. Meanwhile slice steak thinly.
Add steak to the pot, stir, cover and cook until steak is about half way done. Steak and peppers would have given out a nice amount of juices too.
Add salt, pepper and thyme. Mix well.
Add enough stock to just cover the beef and veggies. Add bay leaf, cover and cook on medium low for about 30 minutes, stirring occasionally.
While soup is cooking, preheat oven to 325. Slice French bread into 1/2 inch slices and lay them out on a baking sheet. Do not grease the baking sheet. Bake bread slices for 20-23 minutes, until nice and crispy. Take out and set aside. Raise oven temperature to 375.
Divide soup among oven-save pots. Place crispy slices of bread on top, as many and will fit, and top off with one or two slices of cheese.
Place soup pots on a baking sheet and bake for 5-8 minutes, until cheese is melted and golden.