preheat oven at 375 degree fahrenheit. Bring 2 cups of water to rolling boil. Season with salt. Slice red potatoes. Drop in water and boil for 3-4 minutes or until par cooked. Drain on a paper towel and set aside while potatoes cook and cool down, slice rest of veggies - squash, bell pepper and eggplant.
to make bechamel - microwave 1 cup of milk in microwave sfe container. set aside. heat 1 tablespoon butter in sauce pan. Add 1 tablspoon flour and cook until raw flavor of flour goes away. 1-2 minutes. Don't let flour turn brown. add warm milk 1/4 cup at time and stir well to avoid lumps. add all of milk and continur cooking until sauce thickens and coat back of a spoon. season wiht salt, nutmeg, and black pepper. set aside.
Spray baking dish with cooking spray. Spread layer of tomato sauce, minced garlic, thyme, re chili flakes, salt and olive oil. Mix well while still leaving wel spread. Drizzle bechamel sauce on the top, swirl into the tomato sauce.
Layer sliced veggies on top. i like to make a spiral stack of vegetable slices for presentation just like ratatouille. Drizzle with olive oil. Sprinkle salt thyme, and black pepper on top
cover with parchment paper. Bake for 55-60 minutes or until all veggies are tender. you will see tomato sauce bubbling on the sides.
let it cool for 5 minutes serve with side of crust bread to scoop the sauce.