Load the Instant Pot. Place the chicken thighs in the Instant Pot, sprinkle with garlic powder, sea salt, and pepper, and pour the water over the chicken.

Cook. Seal the Instant Pot and cook on high pressure for 20 minutes. Manually release the pressure.

Shred. Transfer the chicken to a cutting board, discard the cooking liquid, and shred the chicken with 2 forks.

Prep. Preheat the oven to 375°F and liberally grease a 9X13-inch casserole dish.

Saute the veggies. Heat the olive oil in a skillet over medium-high heat. Add the onion, season with salt, and saute until translucent. Add the veggies and saute for another minute or two.

Make the filling. Beat the cream cheese on medium-high speed until smooth. Mix in the sour cream, cottage cheese, condensed cream of chicken soup, ¾ cup cheddar cheese, and the ranch seasoning mix. Fold in the shredded chicken and sauteed veggies.

Make the topping. In a food processor, pulse the Ritz crackers until they are crumbled. Then add the melted butter and pulse until fully incorporated.

Assemble. Spread the chicken mixture evenly into the prepared baking dish and sprinkle the remaining shredded cheddar cheese over the top. Sprinkle the Ritz cracker mixture over the top of the cheddar.

Bake. Bake for 35 minutes or until the casserole is bubbly and the topping is golden brown.