Bring a large saucepan of salted water to the boil for the spaghetti and greens. Trim the baby broccoli and cut into thirds, halving any thick stems lengthwise.
Step 2 — Prep ingredients
Finely chop the onion. Crush or finely chop the garlic. Strip the thyme leaves, discarding the tough stems. Finely chop the chives. Finely grate the parmesan. Crumble 1 stock cube* into a heatproof jug, add 125ml (½ cup) boiling water and stir to dissolve.
Step 3 — Cook spaghetti and greens
Add three-quarters of the spaghetti* to the pan of boiling water (if you're tempted to throw in all the spaghetti, just note the dish won't be as saucy). Cook, stirring occasionally, for 8 mins. Add the baby broccoli and cook for 2 mins. Add the peas and cook for a further 2 mins or until the spaghetti is al dente and the greens are tender. Drain, then return to the pan.
Step 4 — Fry onion and garlic
While the spaghetti is cooking, melt 25g butter in a medium deep frypan over medium-high heat. Cook the onion and garlic, stirring regularly, for 3-4 mins until softened.
Step 5 — Make sauce
Add 2 tsp flour to the onion mixture and cook, stirring, for 1 min or until golden. Gradually add the stock and 125ml (½ cup) milk, stirring constantly to prevent lumps forming. Bring to a simmer and cook, stirring, for 3-4 mins until thickened. Stir in the thyme and parmesan. Remove from the heat.
Step 6 — Get ready to serve
Add the spaghetti, greens and spinach to the sauce and toss for 30 secs or until the spinach is wilted. Taste, then season with salt and pepper. Divide the spaghetti among bowls and scatter with the chives to serve.