Add 470 g Butter beans to the slow cooker along with 400 g Chopped tomatoes, 1 Red onion (diced), 2 tablespoon Sun-dried tomato pesto, a2 pinch Sea salt, and 4 pinch Ground black pepper.
Stir everything together well so the pesto is evenly distributed through the tomatoes and coats the beans.
Put the lid on and cook on high for 2 hours. The sauce should be gently bubbling around the edges and the onion should be softened.
About 15 minutes before the end of the cooking time, stir in 60 g Spinach.
Put the lid back on and cook until the spinach has wilted into the sauce.
Taste and adjust the seasoning if needed. Squeeze 2 tablespoon Lemon juice over the top and sprinkle 15 g Parmesan (grated) on top. Mix well and serve.
Notes
Drain and rinse the butter beans well before adding them.
Do not add the spinach at the beginning. It cooks down very quickly and is much better stirred in near the end so it keeps some colour and freshness.
Be careful with salt at the start. Sun-dried tomato pesto and Parmesan can both be salty, so season lightly first, then adjust after cooking.
If your sauce looks a little thin at the end, leave the lid off for 10 to 15 minutes on high to let it reduce slightly. If it looks too thick, add a small splash of water.
Use lemon juice right before serving rather than cooking it into the sauce. That fresh acidity is what brightens the whole dish.