Combine rinsed lentils, beef broth, and 0.25 tsp salt in a medium saucepan. Bring to a boil over high heat.

Reduce heat to a steady simmer and cook uncovered for 18 to 20 minutes, until lentils are just tender but still hold their shape. Drain through a fine-mesh sieve and set aside.

Heat oven to 220 C / 425 F. Spread cherry tomatoes, zucchini, and red bell pepper on a rimmed sheet pan in a single layer.

Drizzle with 1.5 tbsp olive oil, season with salt and pepper, and toss to coat. Roast for 20 to 22 minutes, until edges are caramelized and tomatoes are blistered.

Stir together Greek yogurt, grated garlic, lemon juice, olive oil, and salt in a small bowl until smooth. Taste and adjust lemon or salt. Set aside or refrigerate until serving.

Heat 1 tbsp olive oil in a 12-inch skillet over medium-high heat. Add diced onion and cook for 3 to 4 minutes, stirring occasionally, until softened and lightly golden.

Add minced garlic and cook for 30 seconds until fragrant. Add ground beef and break it up with a wooden spoon. Cook for 6 to 7 minutes, without stirring too much, until beef is fully browned with no pink remaining.

Drain excess fat if needed, leaving about 1 tbsp in the pan. Add smoked paprika, cumin, coriander, remaining salt, and black pepper. Stir and cook for 1 minute until spices are fragrant.

Add drained lentils to the skillet and stir to combine with the beef. Cook together for 2 to 3 minutes over medium heat, stirring occasionally, until the mixture is hot and the flavors have merged.

Divide fresh baby spinach across four bowls as a base. Spoon a generous portion of the beef and lentil mixture over the spinach.

Top each bowl with roasted vegetables, then drizzle with garlic yogurt. Garnish with chopped parsley and a lemon wedge on the side. Serve immediately.