I finally found a widget that works for recent comments (in the right-hand sidebar). I should have found it ages ago, but I'm lazy.
Besides, as you see, I'm fed up with the grassy background. For the moment, I prefer this "wide brown land" look. Maybe it's the scorching heat in France that has altered my outlook.
Since writing that last paragraph, I've changed the brown background to a subtle greenish hue... which probably corresponds to what the French designate poetically as "goose shit".