This is a simple pasta with two elements: caramelized onions, and a gremolata. I use gremolatas quite a bit. It's a simple parsley, garlic, & lemon topping that can transform a soup, grilled meat, or in this case a pasta. I actually always make one for topping a minestrone. I have changed out parsley for oregano, added SnP, olive oil, even shallots. But this version is the most direct.
Begin with an onion, thinly sliced, red pepper flakes, and kosher salt. At the same time, start your pasta water for 1 lb. of linguine.
Saute the onions in 1 Tbl of olive oil and 1 Tbl of butter for about 15 minutes, or until golden. If some pieces are becoming too dark you can turn the heat down to wait for all the bits to catch up. Then add in 1 jalapeno, seeded, sliced, then minced, and cook for 2 minutes to soften.
Off the heat, and add in4 Tbl of butter, cut into slices to melt quickly, and stir until blended.
Stir in 3 Tbl of lemon juice to the onion & butter sauce. Keep warm.
Chop 1/3c of parsley, 1 tsp of lemon zest, and 1 clove of garlic.
Continue chopping until all three elements are evenly blended.
After your 1 lb of pasta has been cooked & drained, place back into the original pot & toss with the onion and butter sauce until well blended. Add in 1/2 c. of grated Parmesan, toss again, and plate, sprinkling your gremolata on top.
P.S. My girls ate this when we came home late....and even they loved it. :D