Put a large pot of salted water on the stove and bring to a boil. Halve each sweet potato lengthwise (or if large, cut each lengthwise into 4 pieces.) Transfer to pot and simmer for about 20 minutes until just barely fork tender all the way through, but not mushy. You want them to retain their shape on the grill.
Drain, being careful not to crush the potatoes, and dry well.
Preheat grill (or indoor grill pan) to high heat. You want it to get super hot for a nice char on the potatoes. Place sweet potatoes on foil-lined baking sheet or platter, then use a fork to lightly flatten each piece (careful not to break them or mash the skin, which is holding it all together.
Drizzle each sweet potato with olive oil, and sprinkle with Chipotle & Roasted Garlic Seasoning.
Grill on each side until lightly charred and crispy. Remove to serving dish and drizzle with chimichurri, then sprinkle with pumpkin seeds and chopped cilantro. Eat!
Add all the chimichurri ingredients to a blender and purée until almost smooth. I like to leave some pretty flecks of the fresh cilantro visible. Transfer to a small bowl and serve extra alongside sweet potatoes and steak.