Using the saute option in the Instant Pot, melt the butter and add oil. Add the sliced garlic. When done, remove and set aside.
Using the saute option in the Instant Pot, cook the onions until soft. Add the minced garlic (not the sliced) and cook for another minute.
Close the lid on the Instant Pot, make sure the knob is on "sealing". Click on manual, and change the time to 7 minutes at high pressure.
Once the 7 minutes is up on the timer, turn the Instant Pot off right away and switch the knob to "venting" (quick release).
In a separate pot with fish stock, cook the spot prawns until they are just done. About 1 minute.
Before serving, stir the dill in the risotto, and top with the sliced garlic, green onions and the spot prawns. Add more parmesan cheese if desired.