When preparing the avocado sauce, hold off on adding the chopped avocado sauce until you get the marinade going.
Pre-heat an oven to 400 degrees.
Scoop out 1/2 cup of the Avocado Chimichurri Sauce, and pour into a separate bowl. Add the beef tips to that bowl, and toss gently to combine.
Let the beef marinade at room temperature for 10 to 15 minutes. Extend the marinade time for less tender cuts of beef (up to 1 hour at room temperature).
Heat a large oven-proof skillet on medium high heat, and spray with oil. When hot, shake the excess marinade off the beef, then add it to the skillet.
Cook the beef for 2 minutes on one, side, then flip to sear for 2 more minutes on the other side.
Move the skillet to the oven to finish cooking. 4 to 5 minutes at 400 degrees should get you medium rare. Adjust based on your stove and preferences but take care not to overcook this tender cut, noting it will continue cooking as it rests. When you move the skillet into the oven, that’s a good time to add the avocado to the chimichurri if you haven’t done so yet.
When cooked to your liking, take the skillet out of the oven and move the beef to a platter. Serve topped with the remaining Avocado Chimichurri Sauce…and a glass of red wine, preferably one that has a spicy element to it.