Preheat oven to 350°; bring 6 quarts of salted water to a boil; add in macaroni and cook, stirring occasionally, 8-10 minutes until al dente; drain and place in a large bowl.
To blanch the spinach: bring 4 quarts salted water to a simmer over med-high heat; have ready a large bowl of ice water and a slotted spoon; add spinach to simmering water (in three or 4 batches) and submerge it.
Let cook about 15 seconds, remove with the slotted spoon, and plunge into the ice water; let spinach cool completely, drain it, and squeeze out the excess water; if the leaves are large, chop them into bite-sized pieces; set aside.
In a blender or food processor, puree the feta cheese with the milk, lemon juice, olive oil, salt, and pepper (blend in two batches, if needed); this will not be completely smooth; there will be very small chunks of cheese remaining.
Stir the cheese mixture into the cooked macaroni; then add the minced rosemary and thyme, garlic, red pepper flakes, olives, cherry tomatoes, and blanched spinach.
Transfer mixture to a 13x9 inch baking dish; sprinkle with parmesan cheese and the mixed herbs.
Bake on the middle shelf 25-30 minutes until the pasta is heated through and the top is slightly browned.