1. Preheat oven to 300°.
2. In a large dutch oven, heat 2 T. olive oil over medium high heat. Season the brisket with salt and pepper and add to the pot.
3. Cook, turning once, until browned, about 10 minutes. Transfer to a platter.
4. Discard the fat in the dutch oven. Add 2 T. olive oil, the yellow onions, garlic, and bay leaves; season with salt and pepper.
5. Cook, scraping up the browned bits, until the onions are softened.
6. Stir in the espresso and 1 cup water.
7. Return the brisket, fat side up, and top with the onion mixture.
8. Bring to a simmer, cover, and transfer to oven; braise until fork tender, about 3 1/2 hours.
9. Transfer brisket to a platter; let rest 15 minutes before thinly slicing.