Step 1

1 For the tuna-anchovy mayonnaise: Combine the egg yolk and 2 teaspoons of the lemon juice in the bowl of a stand mixer fitted with a balloon-whisk attachment; beat on medium-high speed

Step 2

2 Gradually drizzle in some of the oil, letting it slide down the side of the bowl

Step 3

3 Beat until thickened, then stop

Step 4

4 Add 2 more teaspoons of the juice, plus the reserved caper brine; this should loosen up the mixture

Step 5

5 Continue to beat (medium-high), drizzling in the remaining oil, to form a thick mayonnaise

Step 6

6 Season lightly with salt

Step 7

7 The yield is about 1 1/4 cups

Step 8

8 Combine the anchovies, the remaining lemon juice and a pinch of the black pepper in a small bowl, stirring to coat, then stir that mixture, and the capers, into the mayonnaise

Step 9

9 Use a fork to mash the tuna in a separate bowl, breaking it up into small pieces

Step 10

10 Stir into the mayonnaise, along with the lemon zest, until well incorporated

Step 11

11 Cover tightly and refrigerate until ready to use (and up to 3 days)

Step 12

12 For the potatoes: Line a baking sheet with paper towels

Step 13

13 Bring a large pot of water to a boil over high heat

Step 14

14 Salt it generously

Step 15

15 Add the sweet potatoes and cook for about 15 minutes, until tender

Step 16

16 Transfer the potatoes to the baking sheet to drain

Step 17

17 Use a spatula to crush each one flat

Step 18

18 Heat a large cast-iron skillet, gradually increasing the heat from low to medium-high

Step 19

19 Add 3 tablespoons of the oil

Step 20

20 Once it is shimmering, add the sweet potatoes and season them with a couple of pinches of the salt

Step 21

21 Press the potatoes into the pan and cook for about 10 minutes, undisturbed, until their bases begin to brown

Step 22

22 Flip the sweet potatoes; add 3 more tablespoons of oil to the pan along with the garlic

Step 23

23 Season with another pinch or two of the salt

Step 24

24 Cook for 5 minutes, watching the garlic and stirring it, as needed, to prevent burning

Step 25

25 Flip the sweet potatoes again and add 2 more tablespoons of the oil and a few sprigs each thyme and rosemary

Step 26

26 Cook for another 5 minutes, then flip the sweet potatoes one more time

Step 27

27 Add the remaining 2 tablespoons of oil and the chorizo

Step 28

28 Cook for 5 minutes more to brown and crisp up the chorizo and render its fat

Step 29

29 Transfer to a platter

Step 30

30 Season lightly with salt, black pepper and the crushed red pepper flakes, if using

Step 31

31 Spoon a few dollops of the mayonnaise over the potatoes