Blot the chuck roast dry with paper towels and season both sides generously with salt and pepper. Heat a drizzle of olive oil in the Instant Pot using the sauté feature; brown each side of roast for 2-3 minutes. Remove beef to a plate and set aside. Add diced onion and sauté until softened (about 3 minutes) scraping up any bits stuck to bottom of the pot, then add garlic and stir for 30 seconds.

Pour in the beef broth and continue scraping bottom of pot. Return the chuck roast back to the pot and seal with the lid. Cook for 60-70 minutes depending on size of roast, then let pressure release naturally for 15 minutes.

Use the valve to release any remaining pressure being careful to avoid any steam (I use a wooden spoon to move the valve). Reserve the broth and place the chuck roast on a cutting board or in a large dish and shred with two forks, discarding any fat.

Follow steps 1-4 but use a large pot over medium high heat instead of the instant pot. Cover with a tight fitting lid and bake in a preheated oven at 275º for 3-4 hours depending on size of roast. Shred as directed above.

Add the beef, onion, garlic, and broth to a slow cooker. Cook on low 6-7 hours or high 3-4 hours until tender. Shred as directed.

In a large bowl, combine the shredded beef, a cup of shredded cheese (up to 2 cups depending on preference and size of roast), cumin, and 1 cup of leftover broth being sure to scoop up some onion and garlic. Taste the beef mixture and add more salt, pepper, and/or cumin if needed.

Place ¼ cup of beef mixture in the center of one tortilla, fold sides over then roll tortilla and secure with a toothpick.

Heat 1 inch of oil over medium heat in a deep, heavy pan. Check oil temperature by dipping a small corner of the tortilla in - if it bubbles, it's ready.

Fry 4-5 flautas at a time for about 3 minutes turning with tongs to ensure even browning; lower temperature if browning too quickly. Remove from the oil when they reach desired doneness and drain on a rack or paper towels. You may need to add a bit more oil to the pan after a few batches - be careful when pouring it in, especially if using an open flame.