How do I make a tiny porch dog friendly and inculde a grill?

If you are saying that your 3 dogs need to "share the space", meaning that they go potty there, plant a shrub at the opposite end away from the slab and teach the dogs to potty behind the shrub. Lots of U-tube videos on teaching them where to potty.

Since it's so narrow, I'd try hanging some planters on a fence if you have one or use hanging planters on wrought iron hooks of different heights.

I'd also try to find smaller scale furniture, keeping your colors to 3 - a soft, main color with two secondary colors. Maybe not having a couch but chairs that can easily be rearranged as needed.

I like all of @Sal85902's advice. I hope they are small dogs! I like the idea of chairs that can be moved around, with maybe a chair or two that can be moved inside for extra seating, too. If you have room, maybe you could make a waist-high folding screen to separate the areas when you are grilling and chilling. Then you won't see the grassy area, but you will still have a view of your hanging plants, trees, or gorgeous mountains (!!!) as you keep hubby company. Best wishes 😇

Another idea for seating would be to build or buy a bench that would fit across the end of the area, that use a couple of chairs across from them. If there is room, put a small table in between. That will give you a nice seating area. Then use the other end for the barbecue. Could you train your dogs to use a cat box behind a tree or perhaps take them for a walk?

HTH

The likelyhood of your dogs pooing while grilling is small, as dogs tend to do their major business in the morning. Cleaning up daily is essential in the summer because the odor can be overpowering (having three dogs myself). I bought my dog a fire hydrant, which he won't use, but he loves the flowers. Grilling is a magnet for my dogs because they smell steak, and your space seems small by your description. So, maybe planting some resilient plants will add color, usefulness and a seperation from the two spaces.