The night before, give your starter a feeding, and again first thing in the morning. Around mid-day start making the bread, so you can bake it and finish in time for dinner.
Put the ingredients into a Bosch or other stand mixer if you have one (I love my Bosch, it's been going strong for over 15 years!): 2 cups starter, 4 cups flour, 10 T. water, 2 tsp. oil, 1 T. sugar, 1 tsp. sea salt in last--also add the garlic powder and Italian seasonings now if you're in a hurry. (You could also mix in a bowl then knead by hand too.) Knead for a minute or so and check the dough to see if it's too sticky or too dry--see the video for more on this. You want it to clean off the sides as it mixes, not be too sticky, and have it hold it's shape if you turn off the mixer, but not dry to the touch. Add more water if it's dry or flour if it's too sticky as needed, just a little at a time. The more you make bread you'll get a feel for this.
Take out the dough hook and let the dough set for a few minutes while you get your pans ready (2 parchment paper lined baking sheets) and lightly flour the counter. If you have something to do for an hour or so before you shape the bread and you've got the extra time, that's fine and will give you a nicer rise, but it's not necessary. You can shape right away if you'd rather or if you're short on time.
Turn the dough out onto a floured countertop. Flour or butter your hands if the dough is still a bit sticky to work with. If ever it sticks to the counter a little, dust with more flour. Lightly turn the dough between your hands on the counter until it's a round ball. Using a bench scraper tool (or dough cutter or whatever you call it), cut the dough into 3 or 4 equal sized loaves. 4 loaves will be skinnier, and 3 loaves will be a little bigger.
Work with one piece at a time... If you already added the seasonings, roll the dough into a long skinny French loaf shape, about 12" long, and place onto the parchment-lined baking sheet.
If you didn't add the seasonings yet, roll your dough ball into a rectangle about 8"x10" or so, it doesn't have to be exact at all. Spread 1 Tablespoon oil around the rolled out dough, and sprinkle garlic powder and Italian seasonings all over. Roll it up from the long side and place seam down onto the parchment-lined baking sheet.
Use a serrated knife to carefully cut diagonal slits into the top of the loaf.
Let rise, about 2-5 hours or more if your house is cold. (If using yeast, it'll probably take less than an hour.) Lightly covering with a plastic wrap sprayed with oil keeps the tops softer. (Spray avocado oil an be found at the store now!)
Preheat oven to 375*.
Mix the egg yolk and milk together well, and brush it over the top of the loaves.
Bake for 20-25 minutes until it's a nice golden brown. Cool on wire racks. (Keep the parchment on the baking sheets for the next step.)
Preheat broiler on oven. (Or you could also toast the bread on your outdoor grill, to keep from heating your house up more!)
Slice into 1/2-3/4" pieces and lay back onto the parchment lined baking sheets. Brush oil on each piece, then broil (or grill) until toasted a fairly dark brown--this way it doesn't get soggy when you add the bruschetta topping.
(You'll likely have extra bread leftover to enjoy for dinner the next day with lots of butter, so you may want to start out with only slicing two loaves for the bruschetta.)