The quality of the pesto is important in this dish so use a good one.
1) Preheat oven to 350 degrees Fahrenheit.
2) Finely mince onion, garlic and pepper in food processor or chopper. Sauté in oil until partially absorbed, add mushrooms and sauté until mushrooms soften a bit. Add tomato sauce, half of the pesto, and wine and allow sauce to simmer while you prepare the rest.
3) In a saucepan, melt margarine and whisk in chickpea flour. When it bubbles, slowly add milk, whisking madly until it thickens. Whisk in the remaining pesto.
4) In a long loaf pan (mine measured 4 1/2 in x 12 in approx), place a thin layer of bechamel. Cover with two uncooked lasagne noodles (it's fine if they overlap a little, or if you have lasagne that's long enough to fill the pan, well and good). Make 4 layers, alternating tomato/mushroom sauce with bechamel and ending with bechamel on top. Sprinkle with parm or cheeze.
5) Cover with foil and bake for about 50 minutes, then uncover and allow top to brown. Serve with a good red wine.
Variation: You can of course make this in a square pan but you'll need more noodles.
Source of recipe: I was thinking about what a "romantic" recipe for 2 would consist of, and came up with this. With a long loaf pan and a good red wine, and something decadent for dessert, you're good to go.