Pre-heat the oven to 375 degrees F.
Sauté the diced onions in about 1 tablespoon of olive oil with ½ tsp of salt, over medium heat in a medium sized enameled Dutch oven. The correct amount of oil will make the onions uniformly glisten, but not pool in the pan. Sauté until the onions are translucent. Try not to brown them. Expect 4-5 minutes
Add the minced garlic to the pot. You do not want the garlic to brown. Stir and sauté for about one minute.
Add the brown rice to the pot and stir to coat each grain with the aromatic infused oil.
Add the splash of wine to deglaze any fond that has developed and stir until the wine has mostly been absorbed by the rice.
Add the chopped peaches, along with 3 cups of the stock, saving the 4th cup of stock for the finishing steps.
Increase the heat to high and bring the pot to a full boil. As things are heating, taste test for seasoning. It probably needs some some salt at this point, but how much depends on the how salty your selected broth is. At this point the broth should be well-seasoned.
Once a full boil is reached, cover the pot and transfer to the 375 degree oven, where it will gently simmer for 50 minutes. Set a timer to remind yourself!
While the risotto is cooking in the oven, prepare the prosciutto. Lay the 4 slices individually on a baking sheet. Place the baking sheet in the oven with the risotto. After 5 minutes, remove the prosciutto, flip the slices over, and place back in the oven. After another 5 minutes, remove the prosciutto and allow to cool. Once cooled, the prosciutto slices should be textured like potato chips. Crush the slices and reserve for plating.
After 50 minutes, remove the risotto from the oven, open it and give it a quick stir. Expect the rice to be fully cooked and properly hydrated, with no residual liquid. The peaches will be very soft.
To finish, stir in the butter, then stir in the remaining 1 cup of broth. Finish by stirring in the Parmesan cheese and the basil. Parmesan cheese can turn stringy if it is over-stirred, and risotto is all about creamy and should never be stringy! One last taste test for seasoning. Stir in a bit more salt only if it needs it.
Finally, plate. Portion the risotto and top with the crushed prosciutto chips.