Turn your Instant Pot onto sauté mode. Once it is hot, add in your oil and butter. Stir well until the butter is completely melted. Add the diced onions to your melted butter.

Sauté the onions for about 3 to 5 minutes until they are fully cooked.

Next, add the chicken broth, salt, pepper, garlic powder and onion powder, dill weed. Pour in the cup of half and half and mix well.

Place your noodles on top of your liquid mixture. Do not stir.

Add the drained tuna fish to the top of your noodles. Make sure the tuna is evenly distributed on top of the noodles. Do not stir.

Pour the can of mushroom soup evenly over the top of your tuna mixture. Do not stir.

Stir the ingredients well. Close the Instant Pot lid by twisting it closed. Push the sealing valve away from you to lock in the pressure.

Set your Instant Pot to high pressure for three minutes.

After your three minutes cooking time, use a hot pad or towel, bring the sealing valve toward you to open and release the pressure.

Once the pressure has been released, open your Instant pot lid.

Give your casserole a good mix.

Add the peas into your Instant Pot Tuna casserole and stir well. Then mix your shredded cheese. into the pot and combine.

Enjoy this delicious comfort food casserole in a owl garnished with fresh parsley or chives. Serve alongside some crusty bread and a crisp salad for the perfect meal.