This hearty pasta favourite, includes about 10 tender large meatballs with the sauce. Poaching the meatballs right in the sauce simplifies cooking and clean-up and ensures there is a good meaty and cheesy flavour throughout the sauce.
Combine tomato sauce and diced tomatoes in large saucepan or Dutch oven. Bring to boil over medium-high heat; reduce heat to low, simmer gently uncovered while making the meatballs, about 15 minutes.
Meanwhile combine beef, breadcrumbs, egg, Worcestershire, onion, garlic, thyme, pepper and salt in a large bowl; with clean hands, mix together gently. Form mixture gently into about ten 2-inch (5 cm) balls. For each meatball, make an indent and insert approx 1 tsp (5 mL) blue cheese or small cube of Cheddar; reform the meatballs to ensure the cheese is covered.
Place the meatballs in the simmering sauce. Cover tightly with lid and poach meatballs in sauce for about 20 minutes, turning the meatballs over half way, until digital instant read thermometer reads 160ºF (71ºC). Serve sauce and meatballs over hot pasta.