In a small dry skillet over medium heat, add the pepitas and toast, stirring frequently, until they are fragrant and begin to pop, about 2–3 minutes. Remove from heat and transfer to a small bowl to cool.

Prepare vegetables

Wash and thoroughly dry the mixed salad greens using a salad spinner or paper towels. Halve the cherry tomatoes. Peel (if desired), seed and slice the cucumber into 1/4" half-moons. Thinly slice the radishes and red onion into rings or half-rings. Place all prepared vegetables into a large mixing bowl.

Make lime vinaigrette

In a small bowl or jar combine 2 tablespoons fresh lime juice, 3 tablespoons extra-virgin olive oil, 1 teaspoon honey, 1 teaspoon Dijon mustard, 1 teaspoon minced garlic, 1 teaspoon salt, and 1 teaspoon freshly ground black pepper. Whisk vigorously (or secure the jar lid and shake) until emulsified. If the dressing is too thick or tart, add up to 1 teaspoon water and taste; adjust salt, honey, or lime to preference.

Assemble salad

Drizzle about half of the lime vinaigrette over the vegetables in the large bowl (you can reserve the remainder to serve on the side). Toss gently and thoroughly to coat the greens and distribute the vegetables evenly.

Finish and plate

Divide the dressed greens and vegetables among 4 plates or bowls. Evenly sprinkle crumbled queso fresco over each salad. Scatter croutons and toasted pepitas on top. Add any additional cracked black pepper or a light pinch of salt to taste. Serve immediately with remaining vinaigrette on the side.