I don't think you'll do any prep in that wrap around part because there's no sink and no stove. For me,that would become a catchall for items to be organized in the pantry. I'd put the pantry there and allocate the current pantry space to make a bigger mudroom. Your mudroom is very tight, only big enough for one person.

so we have some prep space in the back.

I agree with emilyam that you're not going to prep in a corner ... away from the action ... away from water and clean-up. Just not gonna happen.

I like MamaGoose's thoughts about mudroom and like the way she "cleaned up" the door issue, but I'm going to take it a step further: Lose the kitchen corner and enlarge the pantry ... and use the extra space to increase the mudroom:

No door into the mudroom ... coats on one side, cabinet on the other side, whatever type of upper cabinets or shelves you think you'd use above. You'd have loads of space here for mail sorting, a trash can, shoes, backpacks, cat's litter box, whatever. You could make this mudroom as narrow as 3' wide or much larger, depending upon how much space you want to allot to the mudroom vs. the pantry.

No door between the mudroom and the pantry ... loads of pantry shelves ... and a second door into the kitchen. Great circulation: A spouse entering from the garage can put away new groceries without disturbing the cook in the modest-sized kitchen.

I LOVE the grocery hatch concept (and I've seen it in real life ONCE, though it was more of a counter-high pass-through instead of a door-on-the-floor), but in this layout you have the option of opening a whole door, which is even better. A door straight from the garage would have to be a full-fledged door just like the one you walk through -- it'd need a lock and would need to meet fire codes.

New topic: Is that your sink and dishwasher on the upper side of the picture? If so, I'd move them over towards the pantry door and the "main kitchen area". You should keep your "main work areas" all on the side nearer the pantry. Use this "back wall", which is bisected by the garage entry pathway as your "secondary stuff area". This is where you keep the coffee pot, where you set a bowl of fruit or a cake. This is the area where you set out drinks and dessert when you have a party. This is the area that keeps your "main work area" free from interruptions.

We like the prep space especially for the window that provides access to the front where we can see who is coming up to the house from the kitchen. I'd hate to lose that.

You can still have the window, it just won't be prep space because you have to take things out of the fridge and bring them to the sink for prep.

We decided on expanding on the kitchen 2.5 feet to add in the french doors and open up the space.

We would like to keep the mudroom connected to the laundry but we do want it bigger than a 4x6.

Is it weird having a walk thru from the mudroom to the pantry? All your food is in there and I wouldn't really want it next to smelly clothes or shoes.

Here's another idea.