Heat the olive oil over medium-high heat in a large nonstick skillet. Add the Andouille sausage and onion and cook until the sausage is browned and the onion is soft. This should take about 5 to 7 minutes. You want to stir frequently, ensuring the flavors meld together nicely.
Next, add the garlic, shrimp, diced tomatoes, and Cajun seasoning. Cook this mixture until the shrimp turns pink, which should be about 3 to 4 minutes. Remember, they’ll cook a bit more in the oven, so you want them slightly undercooked at this stage.
Drain off any excess liquid and stir in the cottage cheese (or ricotta cheese). Set this mixture aside while you prepare the sauce.
In a medium saucepan, melt 1/4 cup of butter. Once melted, add the all-purpose flour and cook while stirring for about 1 minute. This will help thicken your sauce.
Gradually whisk in the milk and bring to a simmer for a few minutes. You'll want it to thicken nicely.
Remove the sauce from heat and stir in the shredded cheddar cheese until it's fully melted and smooth. This cheesy sauce is the magic that brings everything together.
Preheat your oven to 350 degrees. Grease a casserole dish, ideally one that is slightly smaller than 9 by 13 inches. A 7 by 11-inch dish works beautifully. You don’t want extra space, or the filling will ooze out during baking.
Spread about 1/2 cup of the shrimp filling on each lasagna noodle and carefully roll it up. Place each roll in the prepared pan seam side down. If any filling falls out, just tuck it back in. The rolls should be snugly packed together.
If you have any extra filling, don't hesitate to spoon it on top of the roll-ups.
Pour the cheese sauce evenly over the roll-ups and sprinkle with shredded Pepper Jack cheese. Cover the dish with foil, making sure the foil doesn’t touch the cheese (spraying the underside with cooking spray can help!). Bake covered for 15 minutes.
After 15 minutes, uncover the dish and bake for an additional 15 minutes. The cheese should be bubbly and golden. Let it rest for a few minutes before serving.
