In a medium sauce pan, melt 1 tbsp of butter.
Add the onion and let it sautee until transparent, then, and garlic and sautee until fragrant and light gold.
Then, add the rice, season with salt, give everything a little stir, and add in the stock. Bring to a gentle boil, cover and let simmer. No peaking! Leave that lid closed the whole time, and let it cook until all the liquid has been absorbed.
While the rice is cooking, lightly roast the walnuts in a frying pan over medium heat. Toss a few minutes until they are fragrant and begin to toast, set aside.
When the rice is done cooking, quickly open the pan, add in the last bit of butter, and the toasted walnuts and cover the pot again for the rice to rest in the steam and finish cooking. Let it sit covered about 10 minutes.
After the 10 minutes of resting time, open the pan and stir to combine.