Cook the onion and chilis in some oil for about 10 minutes. Add the rice and cook another 5 minutes to coat with the oil. Season with salt and pepper.
Add the lime and then the gin and stir to combine, scraping the pan if necessary to get any browned bits off the bottom. Cook 2 minutes. Add the tonic and continue to stir.
Add about 1 cup of the stock and stir well, continuing to gradually add stock, stir, and cook as needed for about a half hour, until the rice is tender. If you run out of stock during this process, but the rice is still undercooked, continue with water.
Remove from heat and add the yogurt, parm, and mint. Stir, taste, and season with salt and pepper as needed.
Meanwhile, sear the scallops in a hot pan to brown on both sides, about a minute or two on each side.
Serve the risotto and top with the scallops. Add lime wedges, sliced cucumber, crispy shallots, and mint.