Step 1

Heat butter and oil in a large cast iron skillet over medium heat. Add onion and sugar and stir to combine. Cook for about 5 minutes, until onions are just starting to brown. Give a good stir and reduce heat to medium low. Continue to cook until onions are brown and caramelized, about an hour, stirring every 10 minutes. Be patient here! You want those onions to be brown and rich with flavor!*

Step 2

Meanwhile, cook the pasta according to package directions, and prepare your vegetables and grate your cheese.

Step 3

When onions are caramelized, stir in the asparagus and cook until al dente, about 5 minutes.

Step 4

Add the peas and the sherry, and cook for another 2 minutes, then toss in the cooked pasta. When well combined, add cheese and toss until cheese is melted and pasta is well coated with onion sauce.

Step 5

Season well with salt and pepper.

Step 6

Serve with extra freshly grated parmesan cheese