Step 1: Brown the Beef. Heat a skillet over medium and cook the ground beef with the onion and garlic until everything is browned and fragrant. Stir in the paprika, thyme, salt, and pepper, then drain off any excess fat to keep the casserole from getting greasy.
Step 2: Mix the Creamy Layer. In a medium bowl, whisk together the sour cream, milk, and 1 cup of the cheddar. If you’re feeling bold, add the pickled jalapeños and a splash of liquid smoke—they give the casserole a fun cowboy-campfire vibe.
Step 3: Assemble in the Slow Cooker. Start with a base layer of potatoes, then spoon on half of the beef mixture. Add half the tomatoes, corn, and beans, then dollop and gently spread half of the creamy mixture over the top. Repeat the whole layering process once more, finishing with the remaining cheese so it melts into a gorgeous, bubbly topping.
Step 4: Cook. Pop the lid on and cook on low for 6–7 hours or high for 3–4 hours, until the potatoes are completely tender and the whole thing is hot and bubbly.
Step 5: Rest & Serve. Let the completed cowboy casserole sit for about 10 minutes so it can settle and thicken. Scoop and serve with chopped scallions or fresh parsley for a bright, fresh finish. To stretch the meal even further, serve over mashed potatoes or steamed rice.