Should bubbles be forming only in center of pot when simmering? (Dutch oven on gas burner) I'm cooking Marcella Hazan's bolognese/ragu recipe using a brand new Le Creuset 7-quart round dutch oven. For the long simmering stage, the recipe says to keep the heat very low, which is what I'm doing. I'm noticing that the bubbles are appearing only at the very center of the pot (presumably because the flame is so small). Around the edges, I'm able to dip my finger in the sauce and keep it submerged without burning, and I can touch the handles and sides of the pot, too. Is this temperature variation typical and/or acceptable?  (I am stirring occasionally, so I guess that might help give everything a turn in the center.)

It tastes OK so far, but I'm just wondering if I should do something differently next time (e.g., using a pot with a smaller diameter or better conductivity, or even trying to simmer in the oven.)
The reason is almost certainly, as you suspected, because the flame is small.  Neither the ceramic coating nor the cast iron body of a Le Creuset dutch oven are going to conduct the heat around the pot very much; it will go into the food basically right above the flame.

The temperature differential in the pot from right over the flame to at the perimeter is doing neither the quality nor safety of your sauce any good.

You want the entire contents of the dutch oven at a safe temperature (at least 140 F, 60 C) as it stews, simmers, braises, or whatever.  It sounds like this is certainly not true for you right now.

I find the best way to do this sort of cookery is not to use the cook top (hob), but rather place the Dutch oven in a slow oven (about 300 F, 150 C).  This will envelope the entire pot with heat, and transmit to the food inside all around.  It will cook more evenly, without much risk of burning, and is very low maintenance.