Heat up a pan with the oil. Add onions, garlic, rosemary, lamb and beef. Cook the meat until just browned. You do not want to dry it out because it is going to continue to cook in the oven.
Add stock to the pan and mix to incorporate.
Add salt, pepper, and tomatoes. Bring to a boil. Reduce the heat and simmer for 4 minutes. Keep stirring, so nothing burns or sticks to the bottom of the pan.
Combine the ricotta and grated lemon rind in a bowl. Add a little salt and pepper for an extra kick. Spread 1 tablespoon on each no-boil noodle.
Spread 2 cups of the sauce in an 11×7 inch pan coated with cooking spray. I love the Le Creuset baking dishes. Seriously NOTHING sticks to them.
Arrange three ricotta-covered noodles, RICOTTA SIDE UP over the sauce. Top with two more cups of sauce. Repeat this process until you end with the remaining sauce on top of the noodles.
Sprinkle with the feta cheese and cover with foil. Bake in the oven for about 40 minutes. Sometimes my oven takes longer. I just keep peeking to make sure it looks “set up” and not too liquidy anymore.
Remove the foil and let the lasagna cool for about 10–15 minutes. This will help it set up a bit more and make it easier for cutting. Sprinkle with the parsley and serve.