In a small saucepan over low heat, melt the butter. Whisk in the water and milk and heat again (if necessary) until the mixture is between 110-120°F. Stir in the yeast until completely dissolved and let sit for 5 minutes.While the yeast rests, combine the flour, sugar and salt in the bowl of a stand mixer. Mix briefly to combine.Add the yeast mixture and egg into the flour. With the dough hook attachment, mix on low until a shaggy dough is formed, scraping down the sides of the bowl as necessary. Increase the speed to medium low and mix for 5-6 minutes. Dough will be sticky, but smooth. Transfer the dough to an oiled bowl, cover and let rise in a warm place for 60 minutes.To make the filling, add all the tomato filling ingredients to a food processor and blend until smooth.Turn the risen dough out onto a lightly floured work surface. Roll it into an 18 x 14-inch rectangle, with the longer edge facing you. Spread the tomato mix evenly edge to edge. Starting on the long side, roll the dough into a tight log.Spray a standard muffin tin with non-stick spray. Slice the log into twelve 1 ½ inch pieces. Place the rolls in a muffin tin, cover and let rise in a warm place for 30 minutes. Meanwhile, preheat the oven to 400ºF.Whisk together the egg wash and generously brush over the risen rolls. Bake for 25 minutes. Let cool for 5 minutes and serve warm.