The ornamental design for a retrieval pan, as shown and described.
FIG. 1 is a top perspective view of a retrieval pan showing my new design;
FIG. 2 is a bottom perspective view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a bottom view thereof;
FIG. 5 is a sectional view along reference line 5-5 of FIG. 4;
FIG. 6 is a sectional view along reference line 6-6 of FIG. 4;
FIG. 7 is a back view thereof;
FIG. 8 is an additional top perspective view thereof; and,
FIG. 9 is a left side view thereof.
Any shading shown represents a contrast in appearance for illustrative purposes and forms no part of the claimed design and does not depict any specific color, material, or texture.