Preheat oven to 350 degrees.
Grease lasagna dish with olive oil.
Spray large skillet with cooking spray and heat on medium high.
Saute onion and garlic for 3 minutes until onion is tender crisp.
Stir broth and rosemary and bring to a boil.
Stir in artichoke hearts and spinach.
Reduce heat, cover and simmer for 5 minutes.
Stir in pasta sauce.
Spread 1/4 of the artichoke mixture in the bottom of the prepared baking dish.
Then top with 5 no-boil lasagna noodles.
Sprinkle 3/4 cup mozzarella cheese over noodles.
Repeat layers 2 more times, ending with artichoke mixture and mozzarella cheese.
Sprinkle crumbled feta on top.
Bake, covered for 40 minutes.
Uncover and bake an additional 15 minutes, or until hot and bubbly.
Let stand 10 minutes before cutting.