Place the milk, flour and the eggs into a blender. Cover and blend until the mixture is smooth. Refrigerate for 30 minutes.
Stir the spinach and the salsa con queso in a medium bowl.
Pour about 3 tablespoons batter into a hot greased nonstick skillet or crepe pan, swirling the skillet to spread the batter over the bottom of the skillet. Cook for 1 minute or until the crepe is golden on both sides. Remove the crepe from the skillet. Repeat, making 16 crepes in all and stacking the cooked crepes.
Place 1/2 slice ham onto each crepe. Top each with 3 tablespoons spinach mixture. Roll up the crepes around the filling. Place the filled crepes seam-side down into 2 (2-quart) shallow microwave-safe baking dishes. Top with the picante sauce and cheese.
Microwave, one dish at a time, on HIGH for 2 minutes or until the cheese is melted.
The chill time is important for this recipe because it allows the bubbles in the batter to subside, which makes the crepes less likely to tear during cooking.