Ingredients :

• The beef — chuck roast or shoulder — This is the base, so choose well. Chuck roast is perfect here: it’s a hard-working muscle, rich in collagen, which will melt during cooking and naturally thicken the sauce. Avoid grilling cuts — they will become stringy. Cut into fairly large cubes (4-5 cm), they will shrink during cooking.
• Chili powder — Not pure Cayenne pepper — real Tex-Mex chili powder, which is a blend of dried chilies, cumin, oregano, and sometimes garlic powder. If you can’t find it easily, mix 2 parts mild paprika with 1 part cumin, half a part oregano, and a pinch of cayenne. It’s almost the same.
• Ground cumin — The spice that truly defines this dish. Freshly ground cumin is more fragrant — if you have whole seeds and a dedicated spice grinder, now is the time to use them. But store-bought ground cumin works just fine too.
• Bell peppers — Preferably green for the slight bitterness they bring to the base of the sauce, rather than red which is too sweet. Cut them into medium pieces — they will almost disappear into the sauce but contribute to the overall taste, discrete and indispensable.