If you want little else, I would sliver the garlic, make stab wounds in the roast, and insert the garlic. I would slice the mushrooms.

OK, So much for the minimalist. Put freshly ground black pepper on the roast. Maybe some onion powder. Sear the roast in a heavy enameled pan. Or cast iron. When it is crown and crusty, add a bit of sodium. I like Worchestershire (L&P). MSG has not killed me yet. Add some beef broth, a bay leaf or two. Carrots and potatoes. Lots of onions. One cannot have too many onions. Celery is good. Parsley is good, too. Dry sherry adds a nice flavor. Use however much water you need. You will have a thin broth. And if you do decide that you want gravy. Add corn starch or make a roux.

The most important thing in cooking is to measure precisely.

This concept came from my mother who is just a terrific cook. I learned from her.

JayR