Press 'Saute' button to 'Sauté More' function to heat up Instant Pot. Wait until it says 'HOT' on the screen (~8mins). Add 1 tbsp unsalted butter + 1 tbsp olive oil in Instant Pot. Pat dry chicken thighs with a paper towel, then season one side of chicken with kosher salt and black pepper. Place chicken on one side of Instant Pot (seasoned side face down) and shrimps on the other side of Instant Pot, brown them for 3.5 minutes. Season the other side of chicken and shrimps with salt and black pepper. Flip chicken and shrimps, brown this side for another 3.5 minutes. Set aside browned chicken, saute shrimps for another 30 seconds - 1 minute. Set aside shrimps (will be used after pressure cooking).

Add sliced sausages in Instant Pot, saute for 3 minutes.

Add in diced onions, green bell peppers, and celery, saute for 2 minutes. Add in minced garlic cloves, tomato paste, dried thymes, dried oregano, smoked paprika, and cayenne pepper, saute for another minute.

Pour in unsalted chicken stock, then deglaze by scrubbing all the flavorful brown bits off the bottom of the pot. Add in soy sauce, give it a quick mix.

Push all ingredients to one side, then add the browned chicken with all its meat juice in Instant Pot. Add well drained jasmine rice in Instant Pot. Pour unsalted chicken stock in Instant Pot. Ensure all the rice is fully submerged in the stock. Layer crushed or diced tomatoes on the very top. Do not mix! With Venting Knob in Venting Position, close the lid, then turn Venting Knob to Sealing Position. Pressure Cook at High Pressure 7 minutes + Natural Release 10 minutes. After 10 minutes, release the remaining pressure by turning Venting Knob to Venting Position. Open the lid carefully.

Add & mix the fully cooked shrimps in jambalaya. Taste the Jambalaya and adjust the seasoning accordingly.

Garnish the Jambalaya with sliced green onion, then serve.