Don't worry, the soil is still cold and the seeds will not germinate readily. You could sow the peas in cells if you wanted. When you sow in April, then the plants will grow quicker without a check in growth. The beetroot seeds definately need some warmth anyway.

Don't know where Jimmy lives but here in Moray it is certainly warm enough to sow seed. You can start off everything but your beetroot and carrots in cells to give a head start, try some broad beans and climbing beans too.

Just remember that your carrots and beetroot need a soil that has not had compost or manure dug into it.

Globe beetroot can be grown in cells.

Once heard a gardening programme that suggested sowing early peas in half pipes or pieces of guttering. The theory was that when they were growing, and presumably the compost held together by the roots, you dig a little trench and slide the whole lot out into it. Might be fun to try it with a few to see how you get on. But West Yorkshire is usually a bit chilly so no need to worry about sowing a bit later.

I've read of that idea too Steragram but haven't tried it myself

I think if I tried it the whole thing would disintegrate when I tried to tip it out but it obviously works for some people!

Yes some serious veggie growers for showing seem to use that method, like you I'd worry it would all fall to pieces!