Into a pan over low heat, add Olive Oil (2 tablespoon). Once warm, add White Onion (1) and cook, stirring, for 5 minutes.
Add 90/10 Lean Ground Beef (1 pound) and cook for 5 minutes, breaking the meat up with a rubber spatula as you go.
Stir Beef Stock Concentrate (1 package) into Water (300 milliliter) until dissolved.
Add to the pan, along with Canned Diced Tomatoes (400 gram) and Tomato Paste (1 tablespoon). Cook, stirring, for 10 minutes, until the water has mostly reduced.
Add Tomato (1 cup), Garlic (1/2 tablespoon), and Basil Pesto (1 tablespoon). Cook, stirring, for 5 minutes.
Serve sauce over Spaghetti (to taste). Garnish with Grated Parmesan Cheese (to taste), Baby Basil (to taste), and Fresh Parsley (to taste).