Nasty Casserole–a creamy, protein-packed taco-style beef and lentil mixture that cooks up easily in the Instant Pot or Crockpot and makes a versatile filling for nachos, burritos, rice bowls, or tacos.

Nasty Casserole
Just looking into the pot you might think this dish looks nasty but you have to believe me that it’s really yummy! Haha! Sometimes the Instant Pot and slow cooker meals I make look less than appetizing but this creamy ground beef lentil mixture is a W. There are so many ways to enjoy this dinner and it makes perfect lunch leftovers too. (Recipe adapted from Nasty Nacho Casserole).
Ingredients/Substitution Ideas
- Lean ground beef–or ground turkey
- Onion–yellow or white
- Kosher salt
- Beef broth–or water and Better than Bouillon
- Brown lentils–I buy them in the bulk section at Winco
- Sweet frozen corn
- Cream cheese
- Taco sauce–I used red, mild
Steps
Turn Instant Pot to saute setting. When display says HOT add in the beef and break it up. Add in the onion and brown for 5 minutes. Drain off excess grease. Stir in the salt.

Pour in the broth and scrape bottom of pot so that nothing is sticking. Turn off Instant Pot.

Sprinkle in the lentils. Dump in the corn, cream cheese and taco sauce (don’t stir).


Cover Instant Pot and secure the lid. Make sure valve is set to sealing. Set manual/pressure cook button to 10 minutes. When time is up let pot sit for 10 minutes and then move valve to venting. Remove the lid.

Stir well.

Serve the filling on top of nachos, wrapped up in a tortilla, plain with a dollop of sour cream and some cheddar cheese on top, on top of rice, etc.

Notes/Tips
- Here are some tasty ways to serve this creamy taco-lentil beef mixture:
- Nacho-style: Spoon it over tortilla chips and top with shredded cheese, sour cream, jalapeños, and green onions.
- Burrito or taco filling: Wrap it up in a flour tortilla with lettuce, cheese, and salsa, or spoon into taco shells.
- Rice bowl: Serve it over rice with avocado, cilantro, and a squeeze of lime.
- Stuffed peppers: Fill halved bell peppers with the mixture and bake with a sprinkle of cheese.
- Plain and simple: Eat it on its own with a dollop of sour cream and shredded cheddar for a high-protein, low-fuss meal.
- This recipe is gluten free (just make sure to check the taco sauce label).
- I used my 6 quart Instant Pot*. You can also make this in a 3 or 8 quart pot.
- Store leftovers in an airtight container* in the refrigerator for up to 4 days or in the freezer for up to 3 months.
- Other recipes you can make with taco sauce are Instant Pot Cheesy Taco Orzo and Fantastic Casserole.
Did you know you can filter the recipes on my website to search by meat type, IP or Crockpot, low carb, gluten free, etc.? Use the filter to find exactly what you are looking for.


Nasty Casserole
- Prep Time: 20 minutes
- Cook Time: 10 minutes (plus 10 minute NPR)
- Total Time: 30 minutes
- Yield: 4–6 servings 1x
Description
A creamy, protein-packed taco-style beef and lentil mixture that cooks up easily in the Instant Pot or Crockpot and makes a versatile filling for nachos, burritos, rice bowls, or tacos.
Ingredients
- 1 pound lean ground beef
- 1 cup diced onion
- 1/4 tsp kosher salt
- 2 cups beef broth
- 2/3 cup brown lentils
- 1 cup sweet frozen corn
- 4 ounces cream cheese
- 1 cup taco sauce (I used red, mild)
Instructions
Instant Pot Instructions:
- Turn Instant Pot to saute setting. When display says HOT add in the beef and break it up. Add in the onion and brown for 5 minutes. Drain off excess grease. Stir in the salt.
- Pour in the broth and scrape bottom of pot so that nothing is sticking. Turn off Instant Pot.
- Sprinkle in the lentils. Dump in the corn, cream cheese and taco sauce (don’t stir).
- Cover Instant Pot and secure the lid. Make sure valve is set to sealing. Set manual/pressure cook button to 10 minutes. When time is up let pot sit for 10 minutes and then move valve to venting. Remove the lid.
- Stir well.
- Serve the filling on top of nachos, wrapped up in a tortilla, plain with a dollop of sour cream and some cheddar cheese on top, on top of rice, etc.
Slow Cooker Instructions:
- Heat a pan over medium high heat. Add in the beef and break it up. Add in the onion and brown for 5 minutes. Drain off excess grease. Stir in the salt. Transfer to the slow cooker.
- Stir in the broth, lentils, corn and taco sauce.
- Cover and cook on low for 4 hours (or until lentils are tender) and then stir in the cream cheese until melted.
- Serve the filling on top of nachos, wrapped up in a tortilla, plain with a dollop of sour cream and some cheddar cheese on top, on top of rice, etc.
- Category: Beef
- Method: Instant Pot
More recipes with lentils…
Instant Pot Ground Turkey Lentil Chili
This healthy, easy pressure cooker turkey lentil chili is the perfect meal for any night of the week. It fills you up without filling you out while still having tons of flavor.
Instant Pot Lentil Lemon Chicken Soup
A brightly flavored chicken and lentil soup based on the Greek Classic avgolemono, which translates as “egg-lemon.” It is a light and healthy soup that can be served for lunch or dinner.
Instant Pot Sausage Lentil Rice Soup
A flavorful hearty soup with chunks of sausage, lentils, rice, fire roasted tomatoes and seasonings. Give it a shot for dinner this week!
Instant Pot Cheesy Chicken and Lentils
Lentils and chicken are pressure cooked with green salsa and black beans to make a creamy one pot dinner. Top it with cheddar, sour cream, cilantro and crunched up tortilla chips for the ultimate Mexican meal.
*Karen Petersen is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com.





Since I wanted this to be a taco filling I added additional dry seasonings. Once it was done cooking, it had way too much liquid. Do you think using only 1 cup of broth will be enough to cook the lentils? Thank you in advance for your reply.
I would worry that 1 cup wouldn’t be enough. I would use 1.5 cups.
I love your recipes, but I often have to rename them so I know what’s in the recipe.
I’ll use this recipes for sloppy joes.
Sloppy Joes is a great idea!
Taste is good. but the overall appearance is off-putting. I think im either going to add chickpeas or diced potatoes to it.
chickpeas or potatoes sound wonderful! love that idea!