What is it.
Seems to be growing in a rather shady area.
Thank you for contacting the Toronto Master Gardeners.
If I’m correct, the plant in your garden is cushion spurge. It’s botanical name is Euphorbia epithymoides but you’ll also see it called by it’s former name Euphorbia polychroma. It is native to east, southeast, and central Europe, Turkey, and Libya. It is an herbaceous perennial known for it’s characteristic cushion shape. It will grow to about 12 inches tall and wide. The buds you can currently see will shortly erupt into bright yellow ‘flowers’. In fact, the flowers are quire insignificant and are surrounded by showy, yellow bracts. The plant does well in full sun to part shade and is drought tolerant. It does self seed so remove the spent flowers if you don’t want additional seedlings.
Note that the sap of the plant is toxic and can cause irritation to skin and eyes.
I’m including a link below to an article on cushion spurge for further reading. It contains a good photo of the plant in full bloom.