Mushroom and onion conchigliette with pesto

I made a meal that put a smile on my face tonight. It’s super simple, and food snobs may scoff, but who needs food snobs anyway, right? This is a meal for the unpretentious working singleton, perhaps. Or a no-frills meal for a┬áno-frills couple. Ingredients: Conchigliette (but any kind of pasta will do) Some chestnut…