Separate chard stems from leaves; cut both in bite-sized pieces. Set aside.
In a deep large skillet, cook bacon or pancetta until browned and crispy. Remove bacon and drain on a paper towel. If desired, leave about 2 tablespoons of fat in the skillet and use it to sauté the vegetables.
Bring a large pot of generously salted water to boiling. Add orecchiette to boiling water. Set timer for 10 minutes.
While pasta is cooking, heat butter and olive oil or bacon fat in a skillet used to cook the bacon. (For added flavor, do not wash skillet to get all the bacon flavor into the sauce.) Sauté shallots and garlic over medium-high heat for 1 minute. Add mushrooms and chard stems, stirring occasionally until softened, about 5-6 minutes. Deglaze pan with white wine to loosen all the bits of flavor from the pan. Add thyme and parsley and season with salt and black pepper. Turn heat on low until pasta and chard leaves are cooked.
After 10 minutes of cooking pasta, add chard leaves and blanche for 2 minutes. Drain, reserving 1 cup of cooking liquid.
Add pasta and chard leaves into skillet with the mushrooms. Place over lowest heat setting. Add crushed red pepper, and about 1/2 cup of reserved pasta water. Add grated cheese and ricotta and stir to until well combined. Add ground nutmeg. Add the cherry tomatoes and sprinkle most of the bacon, saving some for garnish. Add more of the pasta water, if needed, to make the sauce creamy. Taste and adjust seasonings with more salt, pepper, red pepper flakes, and nutmeg.
Divide among four bowls. Top each serving with 1 tablespoon ricotta, if desired. Add additional grated cheese and the rest of the pancetta.