This hearty Crockpot Lasagna is delicious, versatile and your kitchen will smell sooooo good. If you are not a meat-eater, substitute the beef with beefy cremini and shiitake mushrooms.
Ingredients
1 tbsp. olive oil
1/2 onion, chopped
2 garlic cloves, minced
1 lb. ground beef
Kosher salt
Freshly ground black pepper
1 tsp. Italian seasoning
3 1/2 c. marinara sauce, divided
16 oz. whole-milk ricotta
1/4 c. freshly grated Parmesan, plus more for garnish
1/4 c. chopped parsley, plus more for garnish
1 (16-oz.) box lasagna noodles, unboiled
Vegetarian
1 ½ lbs. cremini mushrooms, chopped
½ lbs. shiitake mushrooms, chopped

Instructions
In a large skillet over medium heat, heat oil. Add onion and cook until translucent, 3 to 4 minutes. Add garlic and cook until fragrant, 1 minute. Add beef and season with salt, pepper, and Italian seasoning. Cook until no pink remains, then drain grease if desired. Stir in 3 cups of the marinara until combined and cook 2-3 minutes.
Vegetarian
Place mushrooms in a large (6 to 8 quart) sauté pan on high or medium-high heat. Stir them with a wooden spoon or shake the pan from time to time. You may hear them squeak.
Sprinkle salt over the mushrooms. The mushrooms will sizzle and then start to release water. (Note that you are not adding fat at this point to the pan; this method of cooking mushrooms in their own moisture is called “dry sautéing.)
Once the mushrooms start to release water into the pan, stir in the chopped onions. Cook until the mushrooms are no longer releasing moisture and the mushroom water has boiled away, about 5 minutes more. Stir in 3 cups of marinara until combined and cook 2-3 minutes.
In a large bowl, combine ricotta with Parmesan and parsley. Season with salt and pepper and stir until fully incorporated.
Grease the bowl of your slow cooker with olive oil. Using the remaining ½ cup of marinara, spread a thin layer on the bottom of the crockpot. Next, add a layer of noodles (break some to make them fit), a layer of mozzarella, and a layer of ricotta mixture. Repeat until all ingredients are used up, ending with mozzarella. Cover and cook on low for 4 to 5 hours.
Garnish with more Parmesan and parsley and serve.