Bring a large pot of salted water to a boil. Wash and dry produce.

Halve, peel, and thinly slice shallot. Remove and discard any large stems from half the kale (all for 4 servings); thinly slice leaves. Peel and mince or grate garlic. 

Heat a large drizzle of olive oil in a large pan over medium-high heat. Add shallot and cook until slightly softened, 1-2 minutes.

Add kale and season with salt and pepper. Cook, stirring, until tender, 5-7 minutes. TIP: If needed, add a splash of water to help soften kale.

Stir in garlic and another drizzle of olive oil. Cook until fragrant, 30 seconds more.

Turn off heat. Remove from pan; set aside.

Once water is boiling, gently add ravioli to pot, then reduce heat to low. Cook, stirring occasionally, until tender and floating to the top, 3-4 minutes. Reserve ½ cup pasta cooking water, then drain.

While ravioli cook, melt 2 TBSP butter (4 TBSP for 4 servings) in pan used for kale over medium heat.

Once butter has melted, add walnuts. Cook, stirring, until walnuts smell toasty and butter is foamy and flecked with amber brown bits, 2-3 minutes.

Add kale mixture to pan with walnuts.

Stir in stock concentrate, crème fraîche, and ¼ cup reserved pasta cooking water (⅓ cup for 4 servings).

Bring to a simmer, then stir in ravioli. Cook, stirring, until ravioli are thoroughly coated in sauce, 1-2 minutes. (Add more pasta cooking water a splash at a time if needed.) Season with salt and pepper. Turn off heat.

Divide pasta between bowls. Sprinkle with Parmesan and serve.