Those are Alium 'globemaster' a type of onion. Unfortunately, the majority of the bulbs only bloom one time, so they are a relatively expensive planting.

They look like Allum " Purple Sensation". The bulbs are planted in autumn. Mine come back year after year.

We definitely used 'globemaster', but yours sound great if they come back repeatedly. We'll look into those in the future

the purple flower is an Allum love them!

Botanical name: Allium spp
Common names: Allium, ornamental onion
USDA zones: 3 to 9, depending on species
Water requirement: Regular water while blooming
Light requirement: Full sun
Mature size: Varies by species
Tolerances/environmental benefits: Drought tolerant, deer and pest resistant