Start by softening the bread. Run it under water until damp, then squeeze out the excess moisture. Tear it into small pieces and place them in a large mixing bowl. This step ensures your meatballs will stay tender and moist.
Add ground chicken, sausage, eggs, Parmesan, grated shallots, garlic, and pepperoncinis to the bowl. Season generously with salt and pepper. Mix everything with your hands until just combined. Be careful not to over-mix, as this can make the meatballs tough.
Coat your hands with a little olive oil to prevent sticking, and roll the mixture into meatballs (about 2 tablespoons each). Place them in a greased 9x13 baking dish. Bake at 450°F for 15 minutes, just until the outsides are browned.
Remove the baking dish from the oven and pour marinara sauce over the meatballs, ensuring they’re well-coated. Cover the dish with foil and bake for 15 more minutes. Then, uncover, sprinkle mozzarella, provolone, and fresh oregano on top, and bake for an additional 10 minutes until the cheese is bubbly and golden.
The heavenly aroma will fill your kitchen! Serve these meatballs warm with your favorite pasta, crusty bread, or a fresh salad. Garnish with extra oregano for a lovely burst of freshness.