In a 12-inch skillet, heat olive oil over medium-high heat. Add the sausage and cook on both sides until browned, about 4-5 minutes. Set the sausage aside.
Add the garlic to the pan and cook until fragrant, about 15 seconds. Add 3/4 of the beans and 1 cup of chicken stock to the skillet and season with salt, pepper and thyme, stir to combine and bring to a simmer over medium heat.
In a medium bowl, smash remaining beans with a fork until a thick paste is formed. Add the smashed beans back into the skillet and stir to combine. Simmer until the beans are heated through and the stock is simmering, about 2-3 minutes.
Add the kale, reduce the heat to medium-low and cook, stirring often until sauce becomes creamy, is slightly reduced and kale has wilted, about 2 minutes more.
Add the parmesan, lemon and sausage to the pan. Stir to combine. Add remaining stock a little at a time if you need more creaminess. Adjust seasoning to taste.
Serve with extra parmesan cheese, red pepper flakes if desired, alongside some crusty bread
The original recipe called for smashing 1/3 of the beans. It was a little too 'creamy'.