In a large frypan, saute off the onion in olive oil until soft.
Add in the garlic and the smokey bacon OR bacon alternative and saute until the fat starts to render.
Add in the rosemary, beef mince OR mushrooms and cooked lentils, and cook until browned.
Add in the balsamic vinegar, VEGEMITE, blitzed sun-dried tomatoes and canned tomatoes. Simmer for 1 hour until the sauce is rich and delicious.
Season at this point (the sauce may not need much seasoning due to the saltiness of the bacon and VEGEMITE).
Serve with al dente spaghetti and a generous sprinkle of freshly grated Parmesan OR nutritional yeast and black pepper.