Add butter to a large saute pan. Once the butter is melted, add the diced onion and garlic. Stir until the onion becomes translucent.
Add the rice, 1/4 tsp sea salt, and roma tomatoes to the pan. Stir to mix it with the onions and garlic. Add the wine and two cups of the broth and cook on medium heat until liquid is almost evaporated. Give this a good stir every couple of minutes.
Once the liquid is almost gone, add in your grape tomatoes, and then continue adding the broth one cup at a time. You should always wait until the broth has cooked into the rice before you add each cup of broth. You should see that the dish is becoming very creamy. Give it a good stir every few minutes.
Once the fourth cup of broth has evaporated, the risotto should be fully cooked. The risotto should be soft and creamy, but not watery. If you think the risotto is hard, add a little water(1/4 cup), stir, and cook it for an additional 5 minutes or until it has cooked into the rice.
Remove it from the heat and stir in the cheese and fresh basil. Then, taste it and add a little salt or pepper to taste. I like to save some of the cheese to use it as a topping when I plate the recipe.