Quick Shepherds Pie!

Okay, so I know the title said quick, but it was not so quick for me.  I think the reason is I prepared it the night before so when I put it in the fridge, it made it very cold and it took even longer to heat up.  If you make it fresh and put it in the oven right away it should not take as long.

Shepherd's Pie
1 lb          Lean ground beef.
1             10.75 oz Condensed Vegetable Soup
1/2 cup    chopped celery
1/2 cup    chopped onion
2 cups     mash potatoes **
3 cups     Colby Jack Shredded Cheese
1 tspn     dried thyme 

1. Heat oven to 350 degrees. 
2. Cook ground beef with the celery and onion until clear. Drain. Add condensed soup and dried thyme. Mix well.
3. Add ground beef mixture to bottom of a rectangular 2.2 quart glass pan. 
4. Spread mash potatoes on top.
5. Put in oven for about 20 minutes. Remove from heat.
6. Sprinkle cheese on top, and place in oven for another 5 minutes until cheese is melted.

** I used the tub of Countrycrock Garlic mash.