Heat 1 tbsp. oil in a large skillet over medium-high heat. Add onions; season with salt and pepper. Cook, stirring, until golden, about 18 minutes. (Reduce heat if onions become too dark.)
Meanwhile, bring a large pot of salted water to a boil. Add cauliflower and red pepper flakes, and cook for 4 minutes. Using a slotted spoon, transfer cauliflower to pan with onions. Cook, stirring, until cauliflower is tender, about 4 minutes. Add kale to cauliflower. Cook, stirring, until kale is tender, about 4 minutes.
Meanwhile, add spaghetti to boiling water; cook according to package instructions. Drain pasta, reserving 1 cup water; add to pan with cauliflower. Add just enough pasta water to create a sauce that coats the pasta. Remove from heat; stir in sardines, lemon juice, and 2 more tbsp. oil. Season with salt and pepper. Serve immediately.
I really enjoyed this recipe and didn't find the sardines overpowered the dish (I used a whole can of sardines and split the dish into five servings I could take in my lunch to work). I did add some garlic, and I sprinkled more crushed red pepper on top of each serving, along with the tiniest bit of parmesan cheese. Delicious!
I was a little anxious making this recipe given Bing28's review, but both my husband and I found it really delicious. In fact, I paused a couple of times while eating it to extol the flavour. If you are not adverse to fish in general, I think you will find this very satisfying.
I should mention that we found the fish taste very mild overall; it just added a new dimension to the meal. And I increased the recipe to 6 servings, throwing in the entire can of sardines so that it wouldn't go to waste
I love sardines but they totally overpowered this dish. (Also, it got even worse/stronger with the leftovers as they sat in the fridge overnight.) I appreciate the creativity of this dish, the presence of all the good veggies and the inclusion of a fatty fish for the protein and good fats, but I'd definitely sub in a less obtrusive protein source next time. (Or, go entirely veg with no meat/fish at all. The pasta/veggies certainly stood on their own before adding the sardines.)