In a bowl, whisk the ingredients for the steak marinade; minced garlic, olive oil and oregano. Season steaks with salt and pepper then rub the garlic marinade over them.
In a baking dish toss the tomatoes together with the olive oil, balsamic vinegar and salt and pepper. Roast them in the oven for about 15 minutes.
To make the polenta, heat the butter together with olive oil. Add minced garlic and continue cooking just until you can smell the garlic. Add heavy cream and water and continue to cook until it starts boiling.
Now you can start grilling the steak, I usually do mine about 7 minutes per side, but it depends how you like yours done.
While the steak is grilling you can finish the polenta. Add the cornmeal to the boiling mixture. You will notice that it quickly thickens. Make sure you whisk quickly as to get rid of any lumps. If you notice the polenta is too thick, add more water, we want it creamu, not too thick, but you don't want it runny either. The polenta needs to cook for about 10 minutes.
To serve, spoon polenta in a dish, top with steak and tomatoes. Drizzle juice from the roasted tomatoes over the steak and polenta and garnish with parsley.
If you have left over polenta, don't throw it away, eat it with some feta cheese and some yogurt or sour cream, it's super delicious.