Mexican Lentil Casserole (Or How I Converted a Skillet Recipe to Instant Pot)

I actually made a recipe conversion that worked, and since that rarely happens, I am writing to tell about it. (My husband tells me to make recipes the way they are written the first time, and then tweak them. I don't often take his advice, not because it's not good or accurate, but because I rarely want to put in the time, effort, or money to make recipes as written.) In this case, I had made the recipe before, mostly as written, but I wanted to make it again as part of a meal plan suggested in an e-mail. That recipe was the Mexican ground beef skillet from Fit Foodie Finds (Funke, 2026). What did I change about the recipe? Well, a lot. Here is the original ingredient list:

1 tablespoon olive oil
1 tablespoon minced garlic
1/2 medium yellow onion, minced
2 large bell peppers, diced
1 lb. 85% ground beef
3 tablespoons homemade taco seasoning
1/2 cup tomato sauce
2 tablespoons green chiles
15 oz. canned black beans, drained and rinsed
1 cup quick-cooking brown rice, quick-cooking white rice works too!
1.5 cups beef broth, any kind
1/2 cup Mexican shredded cheddar cheese

First of all, I did not have ground beef, but I had lots of lentils. I read that I could substitute one cup of lentils for one cup of ground beef (Prakash, 2020), so I swapped that out. I didn't have green chiles, so I swapped the tomato sauce and green chiles out for an equivalent amount of mild salsa/picante sauce. I didn't have black beans and did not want to buy more of those, either (the name of this recipe game was to use things up), so I substituted another cup of lentils. That was probably more than I needed (as one cup of lentils yields about two-and-a-half cups of cooked lentils, more than the one-and-three-quarters to two cups of black beans in a can), but oh well. I did not have quick-cooking brown rice, but I had regular, so I substituted that. I lacked beef broth and nope, wasn't going to buy it, so used a combination of chicken broth and water. I had the cheese, but that was for later.

I would need to cook the lentils, as well as the rice. I usually cook rice in the Instant Pot, and after success with the Instant Pot black beans and rice from Cozy Peach Kitchen in our capsule meal plan, I felt fairly certain that I could convert this recipe to Instant Pot as well (Reeser ,2026). Part of the appeal of the Instant Pot is convenience, so I skipped the olive oil and the step of sautéing the vegetables and just threw everything into the pot. I read that lentils require two cups of water per cup (Vora, 2021), and I knew from my favorite brown rice recipe that it takes one cup of water per cup (Stone, 2025). That lead me to a grand total of five cups of water. Lentils only take 10 minutes maximum to cook in the Instant Pot (Vora), but I knew brown rice needs longer (Stone). The black beans and rice took 28 minutes to cook, so I settled on 22 minutes cook time, with a natural release, and let the pot do it's thing. After all was said and done, I stirred the mixture to distribute the ingredients, divided the servings up into meal prep containers and topped with cheese for later reheating. The result was surprisingly delicious: a one dish meal, hearty, with layers of flavor, and good for us to boot!

So if you want the recipe written out my way, here it is. Layer in the Instant pot in this order [I learned that order matters from the black beans and rice recipe (Reeser, 2026)]:

1 T minced garlic
1/2 onion, chopped
2 green peppers, chopped
2 c brown lentils, rinsed
1 c brown rice, rinsed
3/4 c salsa
3 T taco seasoning [I did use Fit Foodie Find's recipe (Richter, 2024).]
5 c water and or broth.

Cook 22 minutes. Natural release pressure. Stir to incorporate ingredients. Top with cheese and/or sour cream and other desired condiments to serve.

--

Readers, tell me: Am I crazy to basically remake a recipe like this? Or am I creative? As I said, all my conversions often result in a mess of dinner, but by God's blessing, this one didn't!

References:

Funke, L. (2026, January 29). Mexican ground beef skillet. Fit foodie finds. https://fitfoodiefinds.com/mexican-ground-beef-skillet-recipe/#wprm-recipe-container-81394

Prakash, S. (2020, October 20). This is how to substitute lentils for ground beef. The kitchn. https://www.thekitchn.com/this-is-how-to-substitute-lentils-for-ground-beef-250272

Reeser, C. (2026, March 11). Instant Pot black beans and rice. Cozy peach kitchen. https://cozypeachkitchen.com/instant-pot-brown-rice-and-black-beans/#recipe

Richter, E. (2024, February 14). Homemade taco seasoning. Fit foodie finds. https://fitfoodiefinds.com/homemade-taco-seasoning/

Stone, R. (2025, January 15). How to cook brown rice. Add a pinch. https://addapinch.com/instant-pot-brown-rice-recipe/

Vora, N. (2021, November 29). How to cook lentils in the Instant Pot. Rainbow plant life. https://rainbowplantlife.com/how-to-cook-lentils-in-the-instant-pot/#wprm-recipe-container-5596