More or less tomatoes can be grilled depending on what you are planning to use them for. The following recipe would be suitable for use in a simple summer salad. Try doubling this recipe to use as a savory fresh tomato sauce over pasta.

Ingredients:

3 medium sized tomatoes 
3 Tablespoons Olive oil 
A pinch of your favorite fresh herbs 
Salt and Pepper to Taste

Directions:

Firstly, slice tomatoes in half, lengthwise, and gently squeeze out seeds. Don't worry about getting them all out. You want to keep the tomato intact.
Now lay tomato halves on dish in a single layer. Drizzle with Olive oil and sprinkle with herbs, salt and pepper. Try using different combinations of herbs for a new taste treat every time. (I like using parsley and chopped basil but oregano, thyme and/or Rosemary would work just as well.)
Place on hot the grill and cook for approximately 5 minutes per side. Now remove tomatoes from grill, place on a plate and slice into bite sized portions. You can even add it to a salad.