Braised Beef Sauce for Pasta

This is a sauce I made up on my own.  It is perhaps a litle less Italianate than the others here, but it is pleasing,
unassuming comfort food.  I hope you will like it.

Ingredients:
A three pound (1.5 kg) beef shoulder roast or similar
One half (120 ml) cup flour
One half teaspoon (2.5 ml) salt
One half teaspoon (3.5 ml) ground black pepper
Three tablespoons (50 ml) olive oil and more as needed
Two tablespoons (30 ml) olive oil for a separate purpose
Two cloves garlic, pressed
One onion, chopped fine
Three stalks celery, chopped fine
Two cups (500 ml) beef or chicken stock
One cup (250 ml) dry white wine
One half teaspoon (2.5 ml) thyme leaves
One tablespoon (15 ml) fresh rosemary leaves
One bay leaf

Method:
Trim and cut the roast into pieces.  The pieces should be about one inch cubes.  Mix the flour, salt and pepper
in a plastic bag big enough to hold the beef - a grocery store bag will do fine but be sure it doesn't have any
holes.  Put the beef chunks in the bag, twist shut, and shake to coat the beef with the flour.  Discard any flour
that does not adhere to the beef.  Warm a crock pot on high heat.
Using a skillet at moderately high heat, brown the beef in olive oil.  Start with three tablespoons of oil and add
more as needed.  Cook a skilletful at a time and transfer the browned meat to the crock pot.
Using the same skillet, sweat covered the garlic, the onion and the celery in two tablespoons olive oil.   When
limp add the wine and the stock and reduce to a thin syrup.  Add this reduction to the crock pot, then add the
rosemary, the thyme and the bay leaf.  When this has been brought to a boil cook on low heat for several hours.
Add salt and pepper to taste midway through this slow cooking.  Serve with pasta of your choice.