1 cup (packed) baby kale or medium spinach leaves
1 bunch flat-leaf parsley, stemmed (about 1 cup)
¼ cup (combined) fresh oregano and thyme leaves
2 large cloves garlic, crushed and peeled
¼ cup roughly chopped fennel fronds
1 tsp. ground fennel or fennel pollen
1 tsp. crushed red pepper
Salt and pepper
½ cup EVOO
⅓ cup sherry or white wine vinegar
4 to 6 boneless sirloin strip or rib eye steaks (3/4 inch thick, 6 to 8 oz. each); or 4 to 6 boneless, skinless chicken breasts (6 to 8 oz. each); or 4 to 6 halibut or cod fillets (6 to 8 oz. each)
Salt and pepper
Olive oil spray, preferably nonaerosol
In a food processor, pulse the kale, herbs, garlic, fennel fronds, ground fennel, crushed red pepper, and salt and pepper until the kale and herbs are finely chopped. Add the EVOO and vinegar and process again until the chimichurri is fairly smooth. Adjust the seasoning and transfer to a small bowl.
Heat a large cast-iron or other nonstick skillet over medium-high. Using paper towels, pat the beef, chicken, or fish dry; season with salt and pepper. Spray the pan with olive oil spray. Add your protein, then spray the top with more oil.
If using beef, cook, turning occasionally, 7 to 8 minutes for medium. If using chicken, cook, turning occasionally, until cooked through, 9 to 10 minutes. If using fish, cook, turning once, until opaque in the center, 6 to 8 minutes. If using beef or chicken, let the meat rest for 5 minutes before serving. If using fish, serve immediately.
Transfer your protein to plates or a platter; top with the chimichurri. Serve with a salad. Here, I tossed romaine, celery, fennel, red onion, and toasted hazelnuts with some EVOO and lemon juice.