Slow-Cooker Creamy Fajita Steak, Potato & Queso Blanco Casserole Step-by-step instructions

Before you start

Before starting, slice the sirloin steak into thin strips, halve the baby gold potatoes, and slice the bell peppers. Have the fajita seasoning and queso blanco measured and ready.

If using a block of queso, cut it into small pieces to help it melt. The slow cooker should be clean and ready to use. No need to preheat it; the layers will cook evenly as the temperature rises.

Instructions

Layer and Cook

1. 1Layer the Ingredients
   Place the sliced sirloin steak in an even layer in the bottom of a 6-quart slow cooker. Scatter the halved baby gold potatoes over the steak, then arrange the sliced bell peppers on top. Sprinkle the fajita seasoning evenly over the vegetables and meat.
   Look for The layers should be evenly distributed with the steak at the bottom.
   Tip For the most flavor, rub the fajita seasoning into the steak before adding the other layers.
2. 2Add the Queso Blanco
   Pour the white queso blanco evenly over the top of the layered ingredients. Use a spoon or spatula to spread it gently, making sure it reaches the edges and coats the peppers and potatoes.
   Look for The queso should cover most of the surface, though some ingredients may peek through.
   Tip If the queso is too thick to pour, warm it slightly in a saucepan until it is pourable.
3. 3Cover and Cook on Low
   Place the lid on the slow cooker and set it to LOW. Cook for 5 hours, or until the potatoes are fork-tender and the steak is cooked through. Avoid opening the lid during cooking to keep the heat steady. Let it rest for 3 minutes before slicing.
   Look for After 5 hours, the potatoes should pierce easily with a fork and the steak should be tender.
   Safe temperature 145°F (63°C) internal temperature (steaks, chops and roasts)
   Tip If your slow cooker runs hot, check at 4 1/2 hours; if it runs cool, allow up to 6 hours.

At the end of the first phase, the slow cooker is filled with layers of raw steak, potatoes, peppers, and queso. The aroma of fajita seasoning and queso fills the kitchen.

After 5 hours on LOW, the potatoes are tender and the steak is cooked through, reaching 145°F (63°C). The queso has melded with the juices into a savory sauce.

Melt and Rest

4. 4Scatter the Pepper Jack
   After the cooking time, uncover the slow cooker and sprinkle the shredded Pepper Jack cheese evenly over the hot casserole. Replace the lid and let it sit for 5 minutes, allowing the cheese to melt into a bubbly blanket.
   Look for The Pepper Jack should be fully melted and creamy, not clumpy.
   Tip For a golden top, transfer the casserole to a broiler-safe dish and broil for 2–3 minutes, watching carefully.
5. 5Check the Steak Temperature
   To ensure the steak is safe to eat, insert an instant-read thermometer into the thickest piece of steak. It should read at least 145°F (63°C). Let the casserole rest for at least 3 minutes before serving.
   Look for The thermometer should register 145°F (63°C) or higher.
   Safe temperature 145°F (63°C) internal temperature (steaks, chops and roasts)
   Tip Resting allows the juices to redistribute, making the steak more tender.

After adding the Pepper Jack and letting it melt, the top becomes a glossy, golden blanket of cheese. The casserole looks bubbly and inviting. The cheese should be fully melted and stretchy. Letting it rest for a few minutes allows the cheese to set slightly, making it easier to serve.

Garnish and Serve

6. 6Serve with Toppings
   Scoop the casserole onto warm plates. Top each serving with diced avocado, a dollop of sour cream, chopped cilantro, and a squeeze of fresh lime juice. Serve immediately while hot and creamy.
   Look for The toppings add color and freshness to the rich, cheesy casserole.
   Tip Warm the plates in a low oven for a few minutes to keep the dish hot longer.

Once topped with avocado, sour cream, cilantro, and lime, the casserole is vibrant and fresh. The colors pop against the creamy cheese. The dish smells of warm spices and citrus. Serve immediately to enjoy the contrast of hot, creamy casserole and cool, bright toppings.

Common mistakes

One common mistake is opening the slow cooker lid to peek, which releases heat and extends cooking time. Another is using a lean cut like tenderloin, which can dry out; sirloin or flank steak works best.

Also, be careful not to over-season, as fajita seasoning can be salty. If the queso curdles or separates, it may be due to high heat or a low-quality cheese; stir gently and consider adding a splash of milk to smooth it out.

How to tell it’s done

The casserole is done when the potatoes are fork-tender and the steak is cooked through. To check the steak, insert an instant-read thermometer into the thickest piece; it should read at least 145°F (63°C).

The queso should be bubbly and the Pepper Jack melted and smooth. Let the casserole rest for at least 3 minutes before serving to allow the juices to settle and the cheese to set slightly.

• Steaks, chops and roasts: 145°F (63°C) in the thickest part, then a 3-minute rest