Make the harissa yogurt: in a small bowl stir together 1 tablespoon plain whole-milk yogurt and 1/2 teaspoon harissa paste until smooth. Taste and adjust — harissa adds heat and smoky chili flavor; the yogurt cools and lends tang. Set aside in the fridge so it stays cool when served.

Prepare the vegetables: peel (if you prefer) and dice the sweet potato into roughly 1/2-inch (1–1.2 cm) cubes so they cook evenly. Stem the kale (run your fingers down the rib) and chop into bite-size ribbons; finely chop the onion and mince the garlic. Uniform pieces ensure even caramelization — the goal is crisp edges and tender centers.

Par-cook the sweet potato in the pan: heat a 10–12 inch skillet over medium-high heat until hot, then add 1 tablespoon olive oil and swirl to coat. Add the diced sweet potato in a single layer (don’t overcrowd — crowding steams instead of browns). Cook undisturbed for 4–5 minutes until the undersides develop a golden-brown crust. This initial sear starts the Maillard reaction that builds deep flavor.

Flip and finish the sweet potato: toss or turn the cubes and continue to cook for another 4 minutes, stirring occasionally so more sides brown. If the pan is getting too dry, add a teaspoon of water and cover for 1–2 minutes to help the sweet potato soften — this balances crisp exterior with tender interior. Season lightly with salt as it cooks to draw out moisture and concentrate flavor.

Add aromatics: push the sweet potato to one side of the pan, add the chopped onion to the empty space with a small splash of oil if the pan looks dry. Reduce heat to medium and sweat the onion 2–3 minutes until translucent and slightly browned — this sweetens and deepens the base flavor. Add the garlic and cook 30–45 seconds until fragrant (don’t burn it; burnt garlic tastes bitter).

Incorporate the kale: add the chopped kale and toss with the sweet potato and aromatics. Kale will initially seem large and coarse; cooking it briefly wilts and softens the leaves while keeping some bite and bright color. Cook 1–2 minutes until wilted but still vivid green. Season with salt and freshly ground black pepper and taste — adjust if necessary.

Create a nest and fry the egg: push the hash to the edges of the pan and create a small flat spot in the center (a nest). Reduce heat to medium-low and crack the large egg into the center. Cook uncovered for 2–3 minutes for a runny yolk with set whites, or 4–5 minutes for a firmer yolk. Cooking gently at medium-low lets the whites set without over-browning while preserving a silky yolk that will run into the hash when cut.

Finish and plate: transfer the sweet potato and kale hash to a warm plate and top with the fried egg. Spoon 1 tablespoon harissa yogurt alongside or dolloped over the egg so the cool tang contrasts with warm, spicy-sweet hash. Sprinkle 1 tablespoon chopped cilantro and a grind of black pepper for fresh herbal lift.

Serve right away: break the yolk with your fork so it mingles with the sweet potato, coating each bite. The contrast between crunchy, caramelized edges and creamy yolk plus the cool, spicy yogurt is the signature of this dish.