Preheat oven to 350 degrees F (175 degrees C).

Prepare pumpkin and onion: Add 1 tablespoon of butter to each pumpkin half and to the halved onion. Season with salt and pepper.

Wrap the onion in aluminum foil.

Roast pumpkin (cut-side up) and foil-wrapped onion for about 45 minutes, until soft and caramelized.

Scoop out the cooked pumpkin and combine with the cooked onion in a food processor. Puree until smooth and season to taste with salt and pepper.

Transfer the pumpkin puree to a bowl and mix in half of the toasted pine nuts.

Cover wonton wrappers with a damp cloth to prevent drying.

Assemble the ravioli: Place a heaping tablespoon of pumpkin puree in the center of a wonton wrapper.

Brush around the filling with beaten egg and cover with another wonton wrapper. Press the edges to seal.

Place the finished ravioli on a sheet tray dusted with flour. Freeze for later use or proceed to cooking.

Prepare the browned sage butter sauce: In a small saucepan, melt the remaining butter over medium heat. Cook until the butter bubbles and turns brown.

Remove from heat and add diced tomatoes, sliced sage, and a squeeze of lemon juice. Season with salt and pepper.

Cook the ravioli in salted boiling water until they float to the top (about 3-5 minutes).

Transfer the cooked ravioli to warm bowls and drizzle with the browned sage butter sauce.

Top with remaining toasted pine nuts and serve.