Prick the sausages all over with a fork. In a large skillet over medium-high heat, heat the olive oil until shimmering.
Add the sausages and cook, turning occasionally, until browned on all sides and cooked through, about 10–15 minutes.
Meanwhile, peel the garlic cloves and thinly slice them. Transfer the sausages to a plate and set aside.
Lower the heat to medium-low. In the same skillet, add the sliced garlic and cook, stirring, until lightly golden and fragrant, about 1–2 minutes.
Increase the heat to medium-high and add the drained cannellini beans. Toss to coat and cook for 5–7 minutes, stirring occasionally, until the beans are heated through and absorb the flavors. Season with salt and pepper to taste.
Slice the sausages into thick rounds (or leave whole, if you prefer). Return them to the skillet with the beans and stir gently to combine. Cook for another 1–2 minutes to warm everything through.
Remove from the heat, sprinkle with chopped parsley, and serve immediately.