B&C plate with dogs, man

Your pottery mark reads "B & Co." and is from L. Bernardaud & Company, a producer of French Limoges. They began manufacturing in 1900, so you at least know that the piece is 20th C. The company went through a major re-organization in 1955, and one of the Bernardaud sons brought in numerous gifted artists around that time. They put out some of their best work then, I am going to guess that your plate is very likely from that period.

To research the name of your artist, which is, indeed, L. Gauvin, one of the tricks I use that is most effective is to take the artist's last name, the type of work you are researching (in this case, either "pottery" or "ceramics"), then run a Google, not under the usual information search perimeters, but by using the Google "Images" search engine, instead. That way, if there are any photos of any artwork posted anywhere on the internet, you will have a photo of it come up in your search. So, in this case, you would want to be prepared to run at least two searches using Google's "Images" files, one using the words "Gauvin pottery," and if that does not turn up anything, you can then try "Gauvin ceramics." (Or vice-versa, of course.)

Since you now also know the name of the company who makes the ceramics, you can use that additional information for further searches. In this case, using "Bernardaud Co. Gauvin." (Again, just be sure to use the "Images" search engine, and not the usual information files.) If there is any photo on the internet concerning your artist, you will see it come up this way. It may take going through several dozens pages of photos, but if it is there, you'll know it.

Unfortunately, do remember that many of these European artists only worked for these pottery companies for short periods, so while the work may be excellent, it is entirely possible for you to have the first piece that can be attributed to him or her being discussed and/or sold.