I sowed these Super Aquadulce broad beans (www.suffolkherbs.com) two weeks ago and they are about ready to be planted on the allotment. Growing through the winter seems to help resist blackfly in spring. The beans were sown in fresh compost and then placed in a heated propagator with a lid on for ten days. But any warm, well-lit surface indoors should bring them on (someone said the warmth on top of a fridge or freezer works).
To ensure a succession in early summer I will sow another row by pushing the beans directly in the ground on the allotment in about four weeks time. These will remain dormant then appear through the soil in March or April. There’s time to do either though you want to avoid sowing direct or planting in snow or icy ground.