Preheat your oven to 425˚F.
Spread your diced beef on a sheet tray lined with parchment or foil. Give it a generous dose of salt. Roast it until it's browned.
In the mentime, cook your onion in a large pot or dutch oven in the oil over medium high heat. Give it a good hit of salt. When it's tender (brown it if you want), ten minutes or so, add the chile powder, cumin, coriander and cayenne. Cook the spices in the fat.
Pour in the beef and any juices in the sheet tray. Stir to combine. (If you're in the mood add a cup of red wine here to deglaze.) Add the juice from the tomatoes and stir to deglaze. Squeeze the tomatoes into pulp into the pot. Add the beef stock.
Bring to a simmer, lower the heat, and simmer for an hour or two. Taste it. Add salt or more seasonings as needed.
If you want it thicker, knead together 2 tablespoons butter with 2 tablespoons of flour (or cornstarch and water), and stir this in till it's the consistency you want. (Sorry these weren't in the ingredient list but you have something on hand don't you? And if you don't this will be even more authentic.)
Serve garnished with the cilantro. Put out bowls of rice, sliced scallions, chiles, cheese, or what you will (we had some radishes we through in there--we're in quarantine, use what you have, and above all, have fun)!