Step 1: Heat the olive oil in a large heavy-bottomed skillet over medium-low heat. Add the sliced shallots and a pinch of salt.
Step 2: Cook the shallots, stirring occasionally, for about 20-25 minutes until they are soft, caramelized, and a deep golden brown color.
Step 3: Add the garlic, red pepper flakes, and the entire tin of anchovies (including the oil). Stir for 2-3 minutes until the anchovies melt into the oil.
Step 4: Add the tomato paste to the skillet. Cook for 5-7 minutes, stirring frequently, until the paste turns a dark rust color and starts to caramelize against the pan.
Step 5: While the paste cooks, boil a large pot of salted water and cook the pasta 2 minutes less than the package directions (very al dente).
Step 6: Reserve 2 cups of pasta water, then drain the noodles.
Step 7: Add 1 cup of pasta water to the shallot mixture and whisk until a glossy sauce forms. Add the pasta and toss vigorously, adding more water as needed until the sauce coats every strand.
Step 8: Remove from heat, stir in the parsley, and serve the Caramelized Shallot Pasta with plenty of grated cheese.