Heat a large pot or skillet over medium heat and add vegetable oil.

When the oil is hot, add the beef chunks. Lightly brown the beef on all sides to seal in the juices.

Next, add chopped onion and bell pepper to the pot. Cook for about 5 minutes, stirring occasionally to allow the vegetables to soften.

Stir in the minced garlic, dried oregano, and season with salt and pepper. Continue cooking for 2 more minutes while stirring occasionally to blend the flavors.

Pour in the beef stock and add a bay leaf to the mixture. Bring it to a low simmer by adjusting the heat.

Once simmering, cover the pot and allow the stew to cook over low heat until the beef becomes tender, about 1 ½ to 2 hours.

To test for tenderness, a fork should easily shred a piece of beef. If desired, remove a portion of the beef and shred it apart with forks or use a potato masher to mash the beef while it is in the pot.

In a separate small measuring cup or mixing bowl, add cold water. Whisk in cornstarch until thoroughly blended to make a slurry.

Slowly pour the cornstarch mixture into the simmering stew, stirring continuously to combine. Let the stew simmer for another 15 minutes, and you will notice it begins to thicken to your desired consistency.

Taste the stew and adjust the seasoning with additional salt and pepper if necessary.

Once the stew has reached the preferred thickness and flavor, serve it warm over a bed of cooked rice.