Boil a large pan of salted water.
Meanwhile, heat a large frying pan on a high heat and add the butter. When it starts to brown (after around 1.5 minutes), add the sliced garlic and chopped sage. Cook until the sage begins to crisp at the edges, around 1 to 2 minutes. Add the juice and zest of the lemon, and season with salt and freshly ground black pepper. Remove from the heat.
Cook the gnocchi and asparagus in the boiling water for 2 to 3 minutes (or until the gnocchi rises to the top). Drain in a colander, then toss in the sage butter until all coated.
Serve in warm bowls, sprinkled with the grated parmesan.
Enjoy with some crusty bread!