In a large Dutch oven, heat 2 tablespoons oil over medium-high heat. Add mushrooms and garlic; cook, stirring occasionally, until golden brown, about 3 minutes. Remove from pot.
Add remaining 1 tablespoon oil to pot. Sprinkle all sides of roast with salt and pepper. Add roast; sear, turning occasionally, until browned on all sides, about 3 minutes per side. Remove from pot.
Add broth, wine, porcini mushrooms, and tomato paste, scraping bottom of pot; bring to a boil. Remove from heat. Add roast; place oregano and reserved mushroom mixture on top of roast. Cover with lid.
Bake until fork-tender, about 1 hour per pound. Let stand for 5 minutes before serving. Garnish with oregano, if desired.
Recipe by Southern Cast Iron at https://southerncastiron.com/beef-roast-with-mushrooms-and-red-wine/