"Tired of boxed pierogis, yet intimidated by the thought of making pierogis from scratch? I was. Here's what I came up with as an alternative: pasta shells stuffed with traditional pierogi fillings. It's an easy, delicious meal your family will love."
Preheat oven to 350 degrees F (175 degrees C). Grease a 9x13-inch baking dish.
Bring a large pot of lightly salted water to a boil. Cook pasta shells in the boiling water, stirring occasionally until tender yet firm to the bite, about 9 minutes. Drain and arrange at the bottom of the baking dish.
Measure 2 cups of water into a microwave-safe bowl. Microwave on high to bring water to a boil, 4 to 5 minutes. Remove water from microwave and immediately add instant mashed potatoes, using a fork to moisten potatoes. Cover and let stand, about 5 minutes.
Stir French-fried onions, Cheddar cheese, bacon bits, and jalapeno into potatoes; mix well to combine. Stuff each pasta shell with a heaping teaspoon of the potato mixture.
Melt butter in a skillet over medium heat. Add onions; cook and stir until translucent and softened, about 5 minutes. Pour butter and onions over stuffed shells. Cover baking dish with aluminum foil.
Bake stuffed shells in the preheated oven until golden, about 45 minutes.