In a small dry pan, toast the pine nuts until lightly browned and smelling fragrant. Pour them onto a plate or piece of wax or parchment paper to cool.
Preheat the oven to 500 degrees. Line a baking sheet with foil that has been lightly sprayed with nonstick cooking spray, such as Pam.
Scatter the cauliflower on the baking sheet. Drizzle with 2 tablespoons of oil, 1 teaspoon each of salt and pepper.
Roast the cauliflower in the oven for 20 to 25 minutes, or until fork tender and lightly browned.
While the cauliflower is roasting, in a medium skillet over medium heat, add the remaining 2 tablespoons of oil and the butter. Once hot, add the tomatoes, oregano stems, and a pinch of salt and pepper.
Stirring often, cook the tomatoes until very soft and coming out of their skins, pushing the oregano stems down into oil so it can be infused. Some leaves will fall off, which is perfectly fine. The oil and juice from the tomatoes should be making a sauce in the bottom of the pan.
Lower the heat to medium low, add the garlic and stir for about 30 seconds. Remove the oregano stems and discard. Taste for seasoning and adjust salt and pepper as desired. Turn the heat off and wait for the cauliflower to finish cooking if necessary.
To serve, add the warm cauliflower to a large bowl. Evenly pour the tomato mixture over.
Sprinkle the pine nuts and basil leaves on top. Top with grated cheese, if desired.
Serve very warm with crusty/artisan bread as a main dish or alongside a protein for a flavorful side dish.