Bring a large pot of salted water to a boil. Wash and dry produce.

Peel and thinly slice garlic. Trim and thinly slice scallions, separating whites from greens.

Once water is boiling, add spaghetti to pot. Cook, stirring occasionally, until al dente, 9-11 minutes.

Reserve 1 cup pasta cooking water (1½ cups for 4 servings), then drain.

While pasta cooks, heat a drizzle of oil in a large, preferably nonstick, pan over medium heat. Crack eggs* into pan; fry to preference, gently basting with hot oil as eggs cook. Season with salt and pepper. (For 4 servings, you may want to cook eggs in batches.)

Turn off heat; transfer eggs to a plate. Cover with foil to keep warm. Reserve pan.

Heat a large drizzle of olive oil in pan used for eggs over medium heat. Add sliced garlic and scallion whites; cook, stirring constantly, until lightly browned, 2-3 minutes.

Turn off heat; whisk in stock concentrates, garlic powder, half the paprika, half the vinegar, ½ cup reserved pasta cooking water, and as many chili flakes as you like (all the paprika, all the vinegar, and ¾ cup reserved pasta cooking water for 4 servings). Whisk until well combined and slightly thickened, 1-2 minutes.

Add drained spaghetti to pan with sauce and return to medium-low heat. Add spinach; stir until pasta is coated and spinach has wilted, 1 minute. TIP: If needed, stir in more reserved pasta cooking water a splash at a time.

Turn off heat; stir in 2 TBSP butter (4 TBSP for 4 servings). Taste and season with salt and pepper.

Divide pasta between shallow bowls. Top with fried eggs, scallion greens, and as many remaining chili flakes as you like. Serve.