Tagliatelle with caramelized onion, rosemary, mascarpone, and toasted walnut

Instructions

1. 1

   Bring a large pot of water to a boil. Once boiling, add enough salt to season it well. Meanwhile, heat a wide skillet over medium-low heat and add 15 ml (1 tbsp) olive oil and the butter.

2. 2

   Add the sliced onions and 4 g (about 1/2 tsp) salt. Cook for 18-20 minutes over medium-low heat, stirring often, until very soft, golden, and caramelized. If they stick too much, add 15-30 ml (1-2 tbsp) water.

3. 3

   While the onions caramelize, preheat the oven to 180 °C / 350 °F. Place the walnuts on a small tray and toast for 6-8 minutes until fragrant. Let them cool slightly.

4. 4

   Add the chopped garlic, fresh rosemary, and the remaining olive oil to the skillet. Cook for 1 minute, stirring, until the garlic is fragrant but not overly browned.

5. 5

   Cook the tagliatelle in the boiling water according to package timing until al dente, usually 8-10 minutes. Reserve 180 ml (3/4 cup) of the pasta cooking water before draining the pasta.

6. 6

   Lower the skillet heat to the minimum. Stir in the mascarpone, grated Parmesan, lemon zest, 15 ml (1 tbsp) lemon juice, and 120 ml (1/2 cup) of the reserved pasta water. Mix until a creamy, glossy sauce forms.

7. 7

   Add the drained tagliatelle to the skillet along with the black pepper and most of the toasted walnuts. Toss for 1-2 minutes, adding a little more pasta water if needed, until the sauce coats the pasta well.

8. 8

   Taste and adjust with the remaining salt if needed. Serve immediately with the remaining walnuts and, if desired, a little extra Parmesan on top.