Spray a large non-stick frying pan with olive oil and set over medium-high heat. Add red onion and garlic to the pan cook for 1-2 minutes, or until just softened.
Add cannellini beans, sage, ripe tomatoes, tomato paste, parsley, vegetable stock and ¼ cup water and cook for 10-15 minutes, or until sauce is thick.
Stir in apple cider vinegar and baby spinach leaves and heat, stir occasionally for 5-10 minutes.
Serve baked beans with Multigrain toast.